1
|
Yip MC, Gonzalez MM, Lewallen CF, Landry CR, Kolb I, Yang B, Stoy WM, Fong MF, Rowan MJ, Boyden ES, Forest CR. Patch-walking: Coordinated multi-pipette patch clamp for efficiently finding synaptic connections. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.30.587445. [PMID: 39185225 PMCID: PMC11343158 DOI: 10.1101/2024.03.30.587445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Significant technical challenges exist when measuring synaptic connections between neurons in living brain tissue. The patch clamping technique, when used to probe for synaptic connections, is manually laborious and time-consuming. To improve its efficiency, we pursued another approach: instead of retracting all patch clamping electrodes after each recording attempt, we cleaned just one of them and reused it to obtain another recording while maintaining the others. With one new patch clamp recording attempt, many new connections can be probed. By placing one pipette in front of the others in this way, one can "walk" across the tissue, termed "patch-walking." We performed 136 patch clamp attempts for two pipettes, achieving 71 successful whole cell recordings (52.2%). Of these, we probed 29 pairs (i.e., 58 bidirectional probed connections) averaging 91 μm intersomatic distance, finding 3 connections. Patch-walking yields 80-92% more probed connections, for experiments with 10-100 cells than the traditional synaptic connection searching method.
Collapse
Affiliation(s)
- Mighten C. Yip
- George W Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 315 Ferst Dr, Atlanta, GA, 30363, USA
| | - Mercedes M. Gonzalez
- George W Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 315 Ferst Dr, Atlanta, GA, 30363, USA
| | - Colby F. Lewallen
- Ocular and Stem Cell Translational Research Section, Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Corey R. Landry
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 315 Ferst Dr, Atlanta, GA, 30363, USA
| | - Ilya Kolb
- GENIE Project Team, Janelia Research Campus Howard Hughes Medical Institute, Ashburn, VA, 20147, USA
| | - Bo Yang
- George W Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 315 Ferst Dr, Atlanta, GA, 30363, USA
| | - William M. Stoy
- Department of Electrical Engineering, Columbia University, New York, NY, 10027, USA
| | - Ming-fai Fong
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 315 Ferst Dr, Atlanta, GA, 30363, USA
| | - Matthew J.M. Rowan
- Department of Cell Biology, Emory University, 615 Michael St, Atlanta, GA, 30322, USA
| | - Edward S. Boyden
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA, USA
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- Howard Hughes Medical Institute, Cambridge, MA, USA
| | - Craig R. Forest
- George W Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 315 Ferst Dr, Atlanta, GA, 30363, USA
| |
Collapse
|
2
|
Deal PE, Lee H, Mondal A, Lolicato M, Mendonça PRFD, Black H, Jang S, El-Hilali X, Bryant C, Isacoff EY, Renslo AR, Minor DL. Development of covalent chemogenetic K 2P channel activators. Cell Chem Biol 2024; 31:1305-1323.e9. [PMID: 39029456 DOI: 10.1016/j.chembiol.2024.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 04/19/2024] [Accepted: 06/19/2024] [Indexed: 07/21/2024]
Abstract
K2P potassium channels regulate excitability by affecting cellular resting membrane potential in the brain, cardiovascular system, immune cells, and sensory organs. Despite their important roles in anesthesia, arrhythmia, pain, hypertension, sleep, and migraine, the ability to control K2P function remains limited. Here, we describe a chemogenetic strategy termed CATKLAMP (covalent activation of TREK family K+ channels to clamp membrane potential) that leverages the discovery of a K2P modulator pocket site that reacts with electrophile-bearing derivatives of a TREK subfamily small-molecule activator, ML335, to activate the channel irreversibly. We show that CATKLAMP can be used to probe fundamental aspects of K2P function, as a switch to silence neuronal firing, and is applicable to all TREK subfamily members. Together, our findings exemplify a means to alter K2P channel activity that should facilitate molecular and systems level studies of K2P function and enable the search for new K2P modulators.
Collapse
Affiliation(s)
- Parker E Deal
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 93858-2330, USA; Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 93858-2330, USA
| | - Haerim Lee
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 93858-2330, USA
| | - Abhisek Mondal
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 93858-2330, USA
| | - Marco Lolicato
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 93858-2330, USA
| | | | - Holly Black
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Seil Jang
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 93858-2330, USA
| | - Xochina El-Hilali
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 93858-2330, USA
| | - Clifford Bryant
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 93858-2330, USA
| | - Ehud Y Isacoff
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA; Weill Neurohub, University of California, Berkeley, Berkeley, CA 94720, USA; Molecular Biophysics and Integrated Bio-imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Adam R Renslo
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 93858-2330, USA.
| | - Daniel L Minor
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 93858-2330, USA; Molecular Biophysics and Integrated Bio-imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA; Departments of Biochemistry and Biophysics, and Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 93858-2330, USA; California Institute for Quantitative Biomedical Research, University of California, San Francisco, San Francisco, CA 93858-2330, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 93858-2330, USA.
| |
Collapse
|
3
|
Rantataro S, Parkkinen I, Airavaara M, Laurila T. Real-time selective detection of dopamine and serotonin at nanomolar concentration from complex in vitro systems. Biosens Bioelectron 2023; 241:115579. [PMID: 37690355 DOI: 10.1016/j.bios.2023.115579] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/30/2023] [Accepted: 08/05/2023] [Indexed: 09/12/2023]
Abstract
Electrochemical sensors provide means for real-time monitoring of neurotransmitter release events, which is a relatively easy process in simple electrolytes. However, this does not apply to in vitro environments. In cell culture media, competitively adsorbing molecules are present at concentrations up to 350 000-fold excess compared to the neurotransmitter-of-interest. Because detection of dopamine and serotonin requires direct adsorption of the analyte to electrode surface, a significant loss of sensitivity occurs when recording is performed in the in vitro environment. Despite these challenges, our single-walled carbon nanotube (SWCNT) sensor was capable of selectively measuring dopamine and serotonin from cell culture medium at nanomolar concentration in real-time. A primary midbrain culture was used to prove excellent biocompatibility of our SWCNT electrodes, which is a necessity for brain-on-a-chip models. Most importantly, our sensor was able to electrochemically record spontaneous transient activity from dopaminergic cell culture without altering the culture conditions, which has not been possible earlier. Drug discovery and development requires high-throughput screening of in vitro models, being hindered by the challenges in non-invasive characterization of complex neuronal models such as organoids. Our neurotransmitter sensors could be used for real-time monitoring of complex neuronal models, providing an alternative tool for their characterization non-invasively.
Collapse
Affiliation(s)
- Samuel Rantataro
- Department of Electrical Engineering and Automation, Aalto University, Maarintie 8, Espoo, 02150, Finland.
| | - Ilmari Parkkinen
- Institute of Biotechnology, HiLife, University of Helsinki, Biocenter 2, Helsinki, 00014, Finland; Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Viikinkaari, 5E, Helsinki, 00014, Finland
| | - Mikko Airavaara
- Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Viikinkaari, 5E, Helsinki, 00014, Finland; Neuroscience Center, HiLife, University of Helsinki, Biomedicum 1, Haartmaninkatu 8, Helsinki, 00014, Finland
| | - Tomi Laurila
- Department of Electrical Engineering and Automation, Aalto University, Maarintie 8, Espoo, 02150, Finland; Department of Chemistry and Materials Science, Aalto University, Kemistintie 1, Espoo, 02150, Finland.
| |
Collapse
|
4
|
Maita F, Maiolo L, Lucarini I, Del Rio De Vicente JI, Sciortino A, Ledda M, Mussi V, Lisi A, Convertino A. Revealing Low Amplitude Signals of Neuroendocrine Cells through Disordered Silicon Nanowires-Based Microelectrode Array. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2301925. [PMID: 37357140 PMCID: PMC10460871 DOI: 10.1002/advs.202301925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 06/06/2023] [Indexed: 06/27/2023]
Abstract
Today, the key methodology to study in vitro or in vivo electrical activity in a population of electrogenic cells, under physiological or pathological conditions, is by using microelectrode array (MEA). While significant efforts have been devoted to develop nanostructured MEAs for improving the electrophysiological investigation in neurons and cardiomyocytes, data on the recording of the electrical activity from neuroendocrine cells with MEA technology are scarce owing to their weaker electrical signals. Disordered silicon nanowires (SiNWs) for developing a MEA that, combined with a customized acquisition board, successfully capture the electrical signals generated by the corticotrope AtT-20 cells as a function of the extracellular calcium (Ca2+ ) concentration are reported. The recorded signals show a shape that clearly resembles the action potential waveform by suggesting a natural membrane penetration of the SiNWs. Additionally, the generation of synchronous signals observed under high Ca2+ content indicates the occurrence of a collective behavior in the AtT-20 cell population. This study extends the usefulness of MEA technology to the investigation of the electrical communication in cells of the pituitary gland, crucial in controlling several essential human functions, and provides new perspectives in recording with MEA the electrical activity of excitable cells.
Collapse
Affiliation(s)
- Francesco Maita
- Institute for Microelectronics and MicrosystemsNational Research CouncilVia Fosso del Cavaliere 100Rome00133Italy
| | - Luca Maiolo
- Institute for Microelectronics and MicrosystemsNational Research CouncilVia Fosso del Cavaliere 100Rome00133Italy
| | - Ivano Lucarini
- Institute for Microelectronics and MicrosystemsNational Research CouncilVia Fosso del Cavaliere 100Rome00133Italy
| | | | - Antonio Sciortino
- Institute for Microelectronics and MicrosystemsNational Research CouncilVia Fosso del Cavaliere 100Rome00133Italy
| | - Mario Ledda
- Institute of Translational PharmacologyNational Research CouncilVia Fosso del Cavaliere 100Rome00133Italy
| | - Valentina Mussi
- Institute for Microelectronics and MicrosystemsNational Research CouncilVia Fosso del Cavaliere 100Rome00133Italy
| | - Antonella Lisi
- Institute of Translational PharmacologyNational Research CouncilVia Fosso del Cavaliere 100Rome00133Italy
| | - Annalisa Convertino
- Institute for Microelectronics and MicrosystemsNational Research CouncilVia Fosso del Cavaliere 100Rome00133Italy
| |
Collapse
|
5
|
Human In Vitro Models of Epilepsy Using Embryonic and Induced Pluripotent Stem Cells. Cells 2022; 11:cells11243957. [PMID: 36552721 PMCID: PMC9776452 DOI: 10.3390/cells11243957] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/25/2022] [Accepted: 12/04/2022] [Indexed: 12/14/2022] Open
Abstract
The challenges in making animal models of complex human epilepsy phenotypes with varied aetiology highlights the need to develop alternative disease models that can address the limitations of animal models by effectively recapitulating human pathophysiology. The advances in stem cell technology provide an opportunity to use human iPSCs to make disease-in-a-dish models. The focus of this review is to report the current information and progress in the generation of epileptic patient-specific iPSCs lines, isogenic control cell lines, and neuronal models. These in vitro models can be used to study the underlying pathological mechanisms of epilepsies, anti-seizure medication resistance, and can also be used for drug testing and drug screening with their isogenic control cell lines.
Collapse
|
6
|
Schulte S, Gries M, Christmann A, Schäfer KH. Using multielectrode arrays to investigate neurodegenerative effects of the amyloid-beta peptide. Bioelectron Med 2021; 7:15. [PMID: 34711287 PMCID: PMC8554832 DOI: 10.1186/s42234-021-00078-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/05/2021] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Multielectrode arrays are widely used to analyze the effects of potentially toxic compounds, as well as to evaluate neuroprotective agents upon the activity of neural networks in short- and long-term cultures. Multielectrode arrays provide a way of non-destructive analysis of spontaneous and evoked neuronal activity, allowing to model neurodegenerative diseases in vitro. Here, we provide an overview on how these devices are currently used in research on the amyloid-β peptide and its role in Alzheimer's disease, the most common neurodegenerative disorder. MAIN BODY Most of the studies analysed here indicate fast responses of neuronal cultures towards aggregated forms of amyloid-β, leading to increases of spike frequency and impairments of long-term potentiation. This in turn suggests that this peptide might play a crucial role in causing the typical neuronal dysfunction observed in patients with Alzheimer's disease. CONCLUSIONS Although the number of studies using multielectrode arrays to examine the effect of the amyloid-β peptide onto neural cultures or whole compartments is currently limited, they still show how this technique can be used to not only investigate the interneuronal communication in neural networks, but also making it possible to examine the effects onto synaptic currents. This makes multielectrode arrays a powerful tool in future research on neurodegenerative diseases.
Collapse
Affiliation(s)
- Steven Schulte
- Department of Informatics and Microsystems and Technology, University of Applied Science Kaiserslautern, 66482 Zweibrücken, Germany
| | - Manuela Gries
- Department of Informatics and Microsystems and Technology, University of Applied Science Kaiserslautern, 66482 Zweibrücken, Germany
| | - Anne Christmann
- Department of Informatics and Microsystems and Technology, University of Applied Science Kaiserslautern, 66482 Zweibrücken, Germany
| | - Karl-Herbert Schäfer
- Department of Informatics and Microsystems and Technology, University of Applied Science Kaiserslautern, 66482 Zweibrücken, Germany
- Department of Pediatric Surgery, Medical Faculty Mannheim, University of Heidelberg, 68167 Mannheim, Germany
| |
Collapse
|
7
|
Stergiopoulos C, Tsopelas F, Valko K. Prediction of hERG inhibition of drug discovery compounds using biomimetic HPLC measurements. ADMET AND DMPK 2021; 9:191-207. [PMID: 35300361 PMCID: PMC8920097 DOI: 10.5599/admet.995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/20/2021] [Indexed: 11/18/2022] Open
Abstract
The major causes of failure of drug discovery compounds in clinics are the lack of efficacy and toxicity. To reduce late-stage failures in the drug discovery process, it is essential to estimate early the probability of adverse effects and potential toxicity. Cardiotoxicity is one of the most often observed problems related to a compound's inhibition of the hERG channel responsible for the potassium cation flux. Biomimetic HPLC methods can be used for the early screening of a compound's lipophilicity, protein binding and phospholipid partition. Based on the published hERG pIC50 data of 90 marketed drugs and their measured biomimetic properties, a model has been developed to predict the hERG inhibition using the measured binding of compounds to alpha-1-acid-glycoprotein (AGP) and immobilised artificial membrane (IAM). A representative test set of 16 compounds was carefully selected. The training set, involving the remaining compounds, served to establish the linear model. The mechanistic model supports the hypothesis that compounds have to traverse the cell membrane and bind to the hERG ion channel to cause the inhibition. The AGP and the hERG ion channel show structural similarity, as both bind positively charged compounds with strong shape selectivity. In contrast, a good IAM partition is a prerequisite for cell membrane traversal. For reasons of comparison, a corresponding model was derived by replacing the measured biomimetic properties with calculated physicochemical properties. The model established with the measured biomimetic binding properties proved to be superior and can explain over 70% of the variance of the hERG pIC50 values.
Collapse
Affiliation(s)
- Chrysanthos Stergiopoulos
- Laboratory of Inorganic and Analytical Chemistry, School of Chemical Engineering, National Technical University of Athens
| | - Fotios Tsopelas
- Laboratory of Inorganic and Analytical Chemistry, School of Chemical Engineering, National Technical University of Athens
| | - Klara Valko
- Bio-Mimetic Chromatography Ltd.Stevenage, Herts, United Kingdom
| |
Collapse
|
8
|
Gao J, Liao C, Liu S, Xia T, Jiang G. Nanotechnology: new opportunities for the development of patch-clamps. J Nanobiotechnology 2021; 19:97. [PMID: 33794903 PMCID: PMC8017657 DOI: 10.1186/s12951-021-00841-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/23/2021] [Indexed: 12/29/2022] Open
Abstract
The patch-clamp technique is one of the best approaches to investigate neural excitability. Impressive improvements towards the automation of the patch-clamp technique have been made, but obvious limitations and hurdles still exist, such as parallelization, volume displacement in vivo, and long-term recording. Nanotechnologies have provided opportunities to overcome these hurdles by applying electrical devices on the nanoscale. Electrodes based on nanowires, nanotubes, and nanoscale field-effect transistors (FETs) are confirmed to be robust and less invasive tools for intracellular electrophysiological recording. Research on the interface between the nanoelectrode and cell membrane aims to reduce the seal conductance and further improve the recording quality. Many novel recording approaches advance the parallelization, and precision with reduced invasiveness, thus improving the overall intracellular recording system. The combination of nanotechnology and the present intracellular recording framework is a revolutionary and promising orientation, potentially becoming the next generation electrophysiological recording technique and replacing the conventional patch-clamp technique. Here, this paper reviews the recent advances in intracellular electrophysiological recording techniques using nanotechnology, focusing on the design of noninvasive and greatly parallelized recording systems based on nanoelectronics.
Collapse
Affiliation(s)
- Jia Gao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chunyang Liao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China. .,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Sijin Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tian Xia
- Division of NanoMedicine, Department of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| |
Collapse
|
9
|
Gao J, Zhang H, Xiong P, Yan X, Liao C, Jiang G. Application of electrophysiological technique in toxicological study: From manual to automated patch-clamp recording. Trends Analyt Chem 2020. [DOI: 10.1016/j.trac.2020.116082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
10
|
Garrido A, Lepailleur A, Mignani SM, Dallemagne P, Rochais C. hERG toxicity assessment: Useful guidelines for drug design. Eur J Med Chem 2020; 195:112290. [PMID: 32283295 DOI: 10.1016/j.ejmech.2020.112290] [Citation(s) in RCA: 125] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/27/2020] [Accepted: 03/27/2020] [Indexed: 02/06/2023]
Abstract
All along the drug development process, one of the most frequent adverse side effects, leading to the failure of drugs, is the cardiac arrhythmias. Such failure is mostly related to the capacity of the drug to inhibit the human ether-à-go-go-related gene (hERG) cardiac potassium channel. The early identification of hERG inhibition properties of biological active compounds has focused most of attention over the years. In order to prevent the cardiac side effects, a great number of in silico, in vitro and in vivo assays have been performed. The main goal of these studies is to understand the reasons of these effects, and then to give information or instructions to scientists involved in drug development to avoid the cardiac side effects. To evaluate anticipated cardiovascular effects, early evaluation of hERG toxicity has been strongly recommended for instance by the regulatory agencies such as U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA). Thus, following an initial screening of a collection of compounds to find hits, a great number of pharmacomodulation studies on the novel identified chemical series need to be performed including activity evaluation towards hERG. We provide in this concise review clear guidelines, based on described examples, illustrating successful optimization process to avoid hERG interactions as cases studies and to spur scientists to develop safe drugs.
Collapse
Affiliation(s)
- Amanda Garrido
- Normandie Univ, UNICAEN, Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), Caen, France
| | - Alban Lepailleur
- Normandie Univ, UNICAEN, Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), Caen, France
| | - Serge M Mignani
- UMR 860, Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologique, Université Paris Descartes, PRES Sorbonne Paris Cité, CNRS, 45 rue des Saints Pères, 75006, Paris, France; CQM - Centro de Química da Madeira, MMRG, Universidade da Madeira, Campus da Penteada, 9020-105, Funchal, Portugal
| | - Patrick Dallemagne
- Normandie Univ, UNICAEN, Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), Caen, France
| | - Christophe Rochais
- Normandie Univ, UNICAEN, Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), Caen, France.
| |
Collapse
|
11
|
Zeng SL, Sudlow LC, Berezin MY. Using Xenopus oocytes in neurological disease drug discovery. Expert Opin Drug Discov 2019; 15:39-52. [PMID: 31674217 DOI: 10.1080/17460441.2020.1682993] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Introduction: Neurological diseases present a difficult challenge in drug discovery. Many of the current treatments have limited efficiency or result in a variety of debilitating side effects. The search of new therapies is of a paramount importance, since the number of patients that require a better treatment is growing rapidly. As an in vitro model, Xenopus oocytes provide the drug developer with many distinct advantages, including size, durability, and efficiency in exogenous protein expression. However, there is an increasing need to refine the recent breakthroughs.Areas covered: This review covers the usage and recent advancements of Xenopus oocytes for drug discovery in neurological diseases from expression and functional measurement techniques to current applications in Alzheimer's disease, painful neuropathies, and amyotrophic lateral sclerosis (ALS). The existing limitations of Xenopus oocytes in drug discovery are also discussed.Expert opinion: With the rise of aging population and neurological disorders, Xenopus oocytes, will continue to play an important role in understanding the mechanism of the disease, identification and validation of novel molecular targets, and drug screening, providing high-quality data despite the technical limitations. With further advances in oocytes-related techniques toward an accurate modeling of the disease, the diagnostics and treatment of neuropathologies will be becoming increasing personalized.
Collapse
Affiliation(s)
- Steven L Zeng
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Leland C Sudlow
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Mikhail Y Berezin
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| |
Collapse
|
12
|
Obien MEJ, Frey U. Large-Scale, High-Resolution Microelectrode Arrays for Interrogation of Neurons and Networks. ADVANCES IN NEUROBIOLOGY 2019; 22:83-123. [PMID: 31073933 DOI: 10.1007/978-3-030-11135-9_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
High-density microelectrode arrays (HD-MEAs) are increasingly being used for the observation and manipulation of neurons and networks in vitro. Large-scale electrode arrays allow for long-term extracellular recording of the electrical activity from thousands of neurons simultaneously. Beyond population activity, it has also become possible to extract information of single neurons at subcellular level (e.g., the propagation of action potentials along axons). In effect, HD-MEAs have become an electrical imaging platform for label-free extraction of the structure and activation of cells in cultures and tissues. The quality of HD-MEA data depends on the resolution of the electrode array and the signal-to-noise ratio. In this chapter, we begin with an introduction to HD-MEA signals. We provide an overview of the developments on complementary metal-oxide-semiconductor or CMOS-based HD-MEA technology. We also discuss the factors affecting the performance of HD-MEAs and the trending application requirements that drive the efforts for future devices. We conclude with an outlook on the potential of HD-MEAs for advancing basic neuroscience and drug discovery.
Collapse
Affiliation(s)
- Marie Engelene J Obien
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland.
- MaxWell Biosystems, Basel, Switzerland.
| | - Urs Frey
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
- MaxWell Biosystems, Basel, Switzerland
| |
Collapse
|
13
|
Sniecikowska J, Gluch-Lutwin M, Bucki A, Więckowska A, Siwek A, Jastrzebska-Wiesek M, Partyka A, Wilczyńska D, Pytka K, Pociecha K, Cios A, Wyska E, Wesołowska A, Pawłowski M, Varney MA, Newman-Tancredi A, Kolaczkowski M. Novel Aryloxyethyl Derivatives of 1-(1-Benzoylpiperidin-4-yl)methanamine as the Extracellular Regulated Kinases 1/2 (ERK1/2) Phosphorylation-Preferring Serotonin 5-HT 1A Receptor-Biased Agonists with Robust Antidepressant-like Activity. J Med Chem 2019; 62:2750-2771. [PMID: 30721053 DOI: 10.1021/acs.jmedchem.9b00062] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Novel 1-(1-benzoylpiperidin-4-yl)methanamine derivatives were designed as "biased agonists" of serotonin 5-HT1A receptors. The compounds were tested in signal transduction assays (ERK1/2 phosphorylation, cAMP inhibition, Ca2+ mobilization, and β-arrestin recruitment) which identified ERK1/2 phosphorylation-preferring aryloxyethyl derivatives. The novel series showed high 5-HT1A receptor affinity, >1000-fold selectivity versus noradrenergic α1, dopamine D2, serotonin 5-HT2A, histamine H1, and muscarinic M1 receptors, and favorable druglike properties (CNS-MPO, Fsp3, LELP). The lead structure, (3-chloro-4-fluorophenyl)(4-fluoro-4-(((2-(pyridin-2-yloxy)ethyl)amino)methyl)piperidin-1-yl)methanone (17, NLX-204), displayed high selectivity in the SafetyScreen44 panel (including hERG channel), high solubility, metabolic stability, and Caco-2 penetration and did not block CYP3A4, CYP2D6 isoenzymes, or P-glycoprotein. Preliminary in vivo studies confirmed its promising pharmacokinetic profile. 17 also robustly stimulated ERK1/2 phosphorylation in rat cortex and showed highly potent (MED = 0.16 mg/kg) and efficacious antidepressant-like activity, totally eliminating immobility in the rat Porsolt test. These data suggest that the present 5-HT1A receptor-biased agonists could constitute promising antidepressant drug candidates.
Collapse
Affiliation(s)
- Joanna Sniecikowska
- Faculty of Pharmacy , Jagiellonian University Medical College , 9 Medyczna Street , 30-688 Kraków , Poland
| | - Monika Gluch-Lutwin
- Faculty of Pharmacy , Jagiellonian University Medical College , 9 Medyczna Street , 30-688 Kraków , Poland
| | - Adam Bucki
- Faculty of Pharmacy , Jagiellonian University Medical College , 9 Medyczna Street , 30-688 Kraków , Poland
| | - Anna Więckowska
- Faculty of Pharmacy , Jagiellonian University Medical College , 9 Medyczna Street , 30-688 Kraków , Poland
| | - Agata Siwek
- Faculty of Pharmacy , Jagiellonian University Medical College , 9 Medyczna Street , 30-688 Kraków , Poland
| | | | - Anna Partyka
- Faculty of Pharmacy , Jagiellonian University Medical College , 9 Medyczna Street , 30-688 Kraków , Poland
| | - Daria Wilczyńska
- Faculty of Pharmacy , Jagiellonian University Medical College , 9 Medyczna Street , 30-688 Kraków , Poland
| | - Karolina Pytka
- Faculty of Pharmacy , Jagiellonian University Medical College , 9 Medyczna Street , 30-688 Kraków , Poland
| | - Krzysztof Pociecha
- Faculty of Pharmacy , Jagiellonian University Medical College , 9 Medyczna Street , 30-688 Kraków , Poland
| | - Agnieszka Cios
- Faculty of Pharmacy , Jagiellonian University Medical College , 9 Medyczna Street , 30-688 Kraków , Poland
| | - Elżbieta Wyska
- Faculty of Pharmacy , Jagiellonian University Medical College , 9 Medyczna Street , 30-688 Kraków , Poland
| | - Anna Wesołowska
- Faculty of Pharmacy , Jagiellonian University Medical College , 9 Medyczna Street , 30-688 Kraków , Poland
| | - Maciej Pawłowski
- Faculty of Pharmacy , Jagiellonian University Medical College , 9 Medyczna Street , 30-688 Kraków , Poland
| | - Mark A Varney
- Neurolixis Inc. , 34145 Pacific Coast Highway #504 , Dana Point , 92629 California , United States
| | - Adrian Newman-Tancredi
- Neurolixis Inc. , 34145 Pacific Coast Highway #504 , Dana Point , 92629 California , United States
| | - Marcin Kolaczkowski
- Faculty of Pharmacy , Jagiellonian University Medical College , 9 Medyczna Street , 30-688 Kraków , Poland
| |
Collapse
|
14
|
Electrophysiological evidence of RML12 mosquito cell line towards neuronal differentiation by 20-hydroxyecdysdone. Sci Rep 2018; 8:10109. [PMID: 29973702 PMCID: PMC6031678 DOI: 10.1038/s41598-018-28357-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 06/07/2018] [Indexed: 01/06/2023] Open
Abstract
Continuous cell lines from insect larval tissues are widely used in different research domains, such as virology, insect immunity, gene expression, and bio pharmacology. Previous study showed that introduction of 20-hydroxyecdysone to Spodoptera cell line induced a neuron-like morphology with neurite extensions. Despite some results suggesting potential presence of neuro-receptors, no study so far has shown that these neuron-induced cells were functional. Here, using microelectrode arrays, we showed that the mosquito cell line, RML12, differentiated with 20-hydroxyecdysone, displays spontaneous electrophysiological activity. Results showed that these cells can be stimulated by GABAergic antagonist as well as nicotinic agonist. These results provide new evidence of neuron-like functionality of 20-hydroxyecdysone induced differentiated mosquito cell line. Finally, we used this new model to test the effects of two insecticides, temephos and permethrin. Our analysis revealed significant changes in the spiking activity after the introduction of these insecticides with prolonged effect on the neuronal activity. We believe that this differentiated mosquito neuronal cell model can be used for high-throughput screening of new pesticides on insect nervous system instead of primary neurons or in vivo studies.
Collapse
|
15
|
Booth MJ, Restrepo Schild V, Downs FG, Bayley H. Functional aqueous droplet networks. MOLECULAR BIOSYSTEMS 2018; 13:1658-1691. [PMID: 28766622 DOI: 10.1039/c7mb00192d] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Droplet interface bilayers (DIBs), comprising individual lipid bilayers between pairs of aqueous droplets in an oil, are proving to be a useful tool for studying membrane proteins. Recently, attention has turned to the elaboration of networks of aqueous droplets, connected through functionalized interface bilayers, with collective properties unachievable in droplet pairs. Small 2D collections of droplets have been formed into soft biodevices, which can act as electronic components, light-sensors and batteries. A substantial breakthrough has been the development of a droplet printer, which can create patterned 3D droplet networks of hundreds to thousands of connected droplets. The 3D networks can change shape, or carry electrical signals through defined pathways, or express proteins in response to patterned illumination. We envisage using functional 3D droplet networks as autonomous synthetic tissues or coupling them with cells to repair or enhance the properties of living tissues.
Collapse
Affiliation(s)
- Michael J Booth
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | | | | | | |
Collapse
|
16
|
Amiri H, Shepard KL, Nuckolls C, Hernández Sánchez R. Single-Walled Carbon Nanotubes: Mimics of Biological Ion Channels. NANO LETTERS 2017; 17:1204-1211. [PMID: 28103039 PMCID: PMC5301282 DOI: 10.1021/acs.nanolett.6b04967] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 01/06/2017] [Indexed: 05/22/2023]
Abstract
Here we report on the ion conductance through individual, small diameter single-walled carbon nanotubes. We find that they are mimics of ion channels found in natural systems. We explore the factors governing the ion selectivity and permeation through single-walled carbon nanotubes by considering an electrostatic mechanism built around a simplified version of the Gouy-Chapman theory. We find that the single-walled carbon nanotubes preferentially transported cations and that the cation permeability is size-dependent. The ionic conductance increases as the absolute hydration enthalpy decreases for monovalent cations with similar solid-state radii, hydrated radii, and bulk mobility. Charge screening experiments using either the addition of cationic or anionic polymers, divalent metal cations, or changes in pH reveal the enormous impact of the negatively charged carboxylates at the entrance of the single-walled carbon nanotubes. These observations were modeled in the low-to-medium concentration range (0.1-2.0 M) by an electrostatic mechanism that mimics the behavior observed in many biological ion channel-forming proteins. Moreover, multi-ion conduction in the high concentration range (>2.0 M) further reinforces the similarity between single-walled carbon nanotubes and protein ion channels.
Collapse
Affiliation(s)
- Hasti Amiri
- Department of Chemistry and Department of Electrical
Engineering, Columbia University, New York, New York 10027, United States
| | - Kenneth L. Shepard
- Department of Chemistry and Department of Electrical
Engineering, Columbia University, New York, New York 10027, United States
- E-mail:
| | - Colin Nuckolls
- Department of Chemistry and Department of Electrical
Engineering, Columbia University, New York, New York 10027, United States
- E-mail:
| | - Raúl Hernández Sánchez
- Department of Chemistry and Department of Electrical
Engineering, Columbia University, New York, New York 10027, United States
- E-mail:
| |
Collapse
|
17
|
Obien MEJ, Gong W, Frey U, Bakkum DJ. CMOS-Based High-Density Microelectrode Arrays: Technology and Applications. SERIES IN BIOENGINEERING 2017. [DOI: 10.1007/978-981-10-3957-7_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
18
|
The emerging role of in vitro electrophysiological methods in CNS safety pharmacology. J Pharmacol Toxicol Methods 2016; 81:47-59. [DOI: 10.1016/j.vascn.2016.03.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 03/30/2016] [Accepted: 03/30/2016] [Indexed: 01/16/2023]
|
19
|
Abstract
PatchXpress, an automated 16-channel parallel patch clamp system, was used to determine inhibition of human ether-a-go-go related gene (hERG) potassium channels by known blockers. A monoclonal cell line stably expressing hERG potassium channels was generated in CHO-KI cells. Results were compared to conventional patch clamp experiments using similar voltage protocols and solutions. Success rates were evaluated for cell recordings under a variety of conditions, including Accumax versus trypsin treatment to harvest cells, single versus double compound additions, and polystyrene versus glass-coated compound plates. We found that the average success rates rose from 27% with trypsin treatment to 38% with Accumax treatment, which improved to 55–65% following long-term culturing using only Accumax to harvest cells. Two drug additions (spaced 1 min apart with suction off) were also found to produce data that more closely matched conventional experiments. Finally, polystyrene versus glass-coated compound plates were evaluated, and we found that for some compounds (but not all), preparation of compound samples in glass-coated plates resulted in inhibition that more closely matched data obtained by conventional experiments. Therefore, we have established an assay to evaluate the ability of compounds to inhibit hERG potassium channels, which closely matches data produced using conventional methods but with much greater throughput.
Collapse
|
20
|
Sjögren E, Andersson S, Sundgren-Andersson AK, Halldin MM, Stålberg O. Assessment of Free Drug Concentration in Cyclodextrin Formulations Is Essential to Determine Drug Potency in Functional In Vitro Assays. J Pharm Sci 2016; 105:2913-2920. [PMID: 27431012 DOI: 10.1016/j.xphs.2016.04.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 04/28/2016] [Accepted: 04/28/2016] [Indexed: 01/08/2023]
Abstract
Cyclodextrins (CD) have the ability to form inclusion complexes with drugs and can be used as excipients to enhance solubility of poorly soluble drugs. To make accurate estimations of the potency of the drug, knowledge of the free drug concentration is important. The aim of this study was to evaluate the applicability of calculated free drug concentrations toward response measurements in a transient receptor potential vanilloid receptor-1 cell-based in vitro assay. This included accounting for potential competitive CD binding of 2 transient receptor potential vanilloid receptor-1 active entities: 1 antagonist, and 1 agonist (capsaicin). Solubility of the CD-drug complexes was measured, and the ligand to substrate affinity in CD formulations was determined according to the phase-solubility technique. The total concentration of antagonist, agonist, CD, and the binding constants between ligands and CD were used to calculate the free concentration of CD ligands. For capsaicin and 2 of the 3 investigated model drugs, the calculated free drug concentration was consistent with the experimental in vitro data while it was overestimated for one of the compounds. In conclusion, the suggested approach can be used to calculate free drug concentration and competitive binding in CD formulations for the application of cell-based drug functionality assays.
Collapse
Affiliation(s)
- Erik Sjögren
- Department of Pharmacy, Uppsala University, BOX 580, Uppsala SE-751 23, Sweden
| | - Sara Andersson
- Department of Pharmacy, Uppsala University, BOX 580, Uppsala SE-751 23, Sweden
| | | | - Magnus M Halldin
- AlzeCure Foundation, Karolinska Institute Science Park, Huddinge SE-141 57, Sweden
| | - Olle Stålberg
- Department of Engineering and Chemical Sciences, Karlstad University, Karlstad SE-651 88, Sweden.
| |
Collapse
|
21
|
Choi S, Yoon S, Ryu H, Kim SM, Jeon TJ. Automated Lipid Bilayer Membrane Formation Using a Polydimethylsiloxane Thin Film. J Vis Exp 2016. [PMID: 27501114 DOI: 10.3791/54258] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
An artificial lipid bilayer, or black lipid membrane (BLM), is a powerful tool for studying ion channels and protein interactions, as well as for biosensor applications. However, conventional BLM formation techniques have several drawbacks and they often require specific expertise and laborious processes. In particular, conventional BLMs suffer from low formation success rates and inconsistent membrane formation time. Here, we demonstrate a storable and transportable BLM formation system with controlled thinning-out time and enhanced BLM formation rate by replacing conventionally used films (polytetrafluoroethylene, polyoxymethylene, polystyrene) to polydimethylsiloxane (PDMS). In this experiment, a porous-structured polymer such as PDMS thin film is used. In addition, as opposed to conventionally used solvents with low viscosity, the use of squalene permitted a controlled thinning-out time via slow solvent absorption by PDMS, prolonging membrane lifetime. In addition, by using a mixture of squalene and hexadecane, the freezing point of the lipid solution was increased (~16 °C), in addition, membrane precursors were produced that can be indefinitely stored and readily transported. These membrane precursors have reduced BLM formation time of < 1 hr and achieved a BLM formation rate of ~80%. Moreover, ion channel experiments with gramicidin A demonstrated the feasibility of the membrane system.
Collapse
Affiliation(s)
- Sangbaek Choi
- Department of Biological Engineering, Inha University; Biohybrid Systems Research Center (BSRC), Inha University
| | - Sunhee Yoon
- Department of Biological Engineering, Inha University; Biohybrid Systems Research Center (BSRC), Inha University
| | - Hyunil Ryu
- Department of Biological Engineering, Inha University; Biohybrid Systems Research Center (BSRC), Inha University
| | - Sun Min Kim
- Department of Mechanical Engineering, Inha University; Biohybrid Systems Research Center (BSRC), Inha University; Convergent Research Center for Metabolism and Immunoregulation (CRCMI), Inha University;
| | - Tae-Joon Jeon
- Department of Biological Engineering, Inha University; Biohybrid Systems Research Center (BSRC), Inha University; Convergent Research Center for Metabolism and Immunoregulation (CRCMI), Inha University;
| |
Collapse
|
22
|
Leung S, Holbrook A, King B, Lu HT, Evans V, Miyamoto N, Mallari C, Harvey S, Davey D, Ho E, Li WW, Parkinson J, Horuk R, Jaroch S, Berger M, Skuballa W, West C, Pulk R, Phillips G, Bryant J, Subramanyam B, Schaefer C, Salamon H, Lyons E, Schilling D, Seidel H, Kraetzschmar J, Snider M, Perez D. Differential Inhibition of Inducible T Cell Cytokine Secretion by Potent Iron Chelators. ACTA ACUST UNITED AC 2016; 10:157-67. [PMID: 15799959 DOI: 10.1177/1087057104272394] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Effector functions and proliferation of T helper (Th) cells are influenced by cytokines in the environment. Th1 cells respond to a synergistic effect of interleukin-12 (IL-12) and interleukin-18 (IL-18) to secrete interferon-gamma (IFN-γ). In contrast, Th2 cells respond to interleukin-4 (IL-4) to secrete IL-4, interleukin-13 (IL-13), interleukin-5 (IL-5), and interleukin-10 (IL-10). The authors were interested in identifying nonpeptide inhibitors of the Th1 response selective for the IL-12/IL-18-mediated secretion of IFN-γ while leaving the IL-4-mediated Th2 cytokine secretion relatively intact. The authors established a screening protocol using human peripheral blood mononuclear cells (PBMCs) and identified the hydrazino anthranilate compound 1 as a potent inhibitor of IL-12/IL-18-mediated IFN-γ secretion from CD3+ cells with an IC50 around 200 nM. The inhibitor was specific because it had virtually no effect on IL-4-mediated IL-13 release from the same population of cells. Further work established that compound 1 was a potent intracellular iron chelator that inhibited both IL-12/IL-18- and IL-4-mediated T cell proliferation. Iron chelation affects multiple cellular pathways in T cells. Thus, the IL-12/IL-18-mediated proliferation and IFN-γ secretion are very sensitive to intracellular iron concentration. However, the IL-4-mediated IL-13 secretion does not correlate with proliferation and is partially resistant to potent iron chelation
Collapse
|
23
|
Dorn A, Hermann F, Ebneth A, Bothmann H, Trube G, Christensen K, Apfel C. Evaluation of a High-Throughput Fluorescence Assay Method for hERG Potassium Channel Inhibition. ACTA ACUST UNITED AC 2016; 10:339-47. [PMID: 15964935 DOI: 10.1177/1087057104272045] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The number of projects in drug development that fail in late phases because of cardiac side effects such as QT prolongation can impede drug discovery and development of projects. The molecular target responsible for QT prolongation by a wide range of pharmaceutical agents is the myocardial hERG potassium channel. It is therefore desirable to screen for compound interactions with the hERG channel at an early stage of drug development. Here, the authors report a cell-based fluorescence assay using membrane potential-sensitive fluorescent dyes and stably transfected hERG channels from CHO cells. The assay allows semiautomated screening of compounds for hERG activity on 384-well plates and is sufficiently rapid for testing a large number of compounds. The assay is robust as indicated by a Z′ factor larger than 0.6. The throughput is in the range of 10,000 data points per day, which is significantly higher than any other method presently available for hERG. The data obtained with the fluorescence assay were in qualitative agreement with those from patch-clamp electrophysiological analysis. There were no false-positive hits, and the rate of false-negative compounds is currently 12% but might be further reduced by testing compounds at higher concentration. Quantitative differences between fluorescence and electrophysiological methods may be due to the use- or voltage-dependentactivity of the antagonists.
Collapse
Affiliation(s)
- Arnulf Dorn
- Hoffmann-La Roche Ltd., Pharma Research, Basel, Switzerland.
| | | | | | | | | | | | | |
Collapse
|
24
|
Abstract
Many high-throughput ion channel assays require the use of voltage-sensitive dyes to detect channel activity in the presence of test compounds. Dye systems employing Förster resonance energy transfer (FRET) between 2 membrane-bound dyes are advantageous in combining high sensitivity, relatively fast response, and ratiometric output. The most widely used FRET voltage dye system employs a coumarin fluorescence donor whose excitation spectrum is pH dependent. The authors have validated a new class of voltage-sensitive FRET donors based on a pyrene moiety. These dyes are significantly brighter than CC2-DMPE and are not pH sensitive in the physiological range. With the new dye system, the authors demonstrate a new high-throughput assay for the acid-sensing ion channel (ASIC) family. They also introduce a novel method for absolute calibration of voltage-sensitive dyes, simultaneously determining the resting membrane potential of a cell. ( Journal of Biomolecular Screening 2007:656-667)
Collapse
Affiliation(s)
- Michael P Maher
- Johnson & Johnson Pharmaceutical Research and Development L.L.C., San Diego, California 92121, USA.
| | | | | |
Collapse
|
25
|
Danker T, Braun F, Silbernagl N, Guenther E. Catch and Patch: A Pipette-Based Approach for Automating Patch Clamp That Enables Cell Selection and Fast Compound Application. Assay Drug Dev Technol 2016; 14:144-55. [PMID: 26991363 DOI: 10.1089/adt.2015.696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Manual patch clamp, the gold standard of electrophysiology, represents a powerful and versatile toolbox to stimulate, modulate, and record ion channel activity from membrane fragments and whole cells. The electrophysiological readout can be combined with fluorescent or optogenetic methods and allows for ultrafast solution exchanges using specialized microfluidic tools. A hallmark of manual patch clamp is the intentional selection of individual cells for recording, often an essential prerequisite to generate meaningful data. So far, available automation solutions rely on random cell usage in the closed environment of a chip and thus sacrifice much of this versatility by design. To parallelize and automate the traditional patch clamp technique while perpetuating the full versatility of the method, we developed an approach to automation, which is based on active cell handling and targeted electrode placement rather than on random processes. This is achieved through an automated pipette positioning system, which guides the tips of recording pipettes with micrometer precision to a microfluidic cell handling device. Using a patch pipette array mounted on a conventional micromanipulator, our automated patch clamp process mimics the original manual patch clamp as closely as possible, yet achieving a configuration where recordings are obtained from many patch electrodes in parallel. In addition, our implementation is extensible by design to allow the easy integration of specialized equipment such as ultrafast compound application tools. The resulting system offers fully automated patch clamp on purposely selected cells and combines high-quality gigaseal recordings with solution switching in the millisecond timescale.
Collapse
|
26
|
Hogstrom LJ, Guo SM, Murugadoss K, Bathe M. Advancing multiscale structural mapping of the brain through fluorescence imaging and analysis across length scales. Interface Focus 2016; 6:20150081. [PMID: 26855758 DOI: 10.1098/rsfs.2015.0081] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Brain function emerges from hierarchical neuronal structure that spans orders of magnitude in length scale, from the nanometre-scale organization of synaptic proteins to the macroscopic wiring of neuronal circuits. Because the synaptic electrochemical signal transmission that drives brain function ultimately relies on the organization of neuronal circuits, understanding brain function requires an understanding of the principles that determine hierarchical neuronal structure in living or intact organisms. Recent advances in fluorescence imaging now enable quantitative characterization of neuronal structure across length scales, ranging from single-molecule localization using super-resolution imaging to whole-brain imaging using light-sheet microscopy on cleared samples. These tools, together with correlative electron microscopy and magnetic resonance imaging at the nanoscopic and macroscopic scales, respectively, now facilitate our ability to probe brain structure across its full range of length scales with cellular and molecular specificity. As these imaging datasets become increasingly accessible to researchers, novel statistical and computational frameworks will play an increasing role in efforts to relate hierarchical brain structure to its function. In this perspective, we discuss several prominent experimental advances that are ushering in a new era of quantitative fluorescence-based imaging in neuroscience along with novel computational and statistical strategies that are helping to distil our understanding of complex brain structure.
Collapse
Affiliation(s)
- L J Hogstrom
- Department of Biological Engineering , Massachusetts Institute of Technology , 77 Massachusetts Avenue, Building 16, Room 255, Cambridge, MA 02139 , USA
| | - S M Guo
- Department of Biological Engineering , Massachusetts Institute of Technology , 77 Massachusetts Avenue, Building 16, Room 255, Cambridge, MA 02139 , USA
| | - K Murugadoss
- Department of Biological Engineering , Massachusetts Institute of Technology , 77 Massachusetts Avenue, Building 16, Room 255, Cambridge, MA 02139 , USA
| | - M Bathe
- Department of Biological Engineering , Massachusetts Institute of Technology , 77 Massachusetts Avenue, Building 16, Room 255, Cambridge, MA 02139 , USA
| |
Collapse
|
27
|
Picones A, Loza-Huerta A, Segura-Chama P, Lara-Figueroa CO. Contribution of Automated Technologies to Ion Channel Drug Discovery. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2016; 104:357-378. [DOI: 10.1016/bs.apcsb.2016.01.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
28
|
Computational investigations of hERG channel blockers: New insights and current predictive models. Adv Drug Deliv Rev 2015; 86:72-82. [PMID: 25770776 DOI: 10.1016/j.addr.2015.03.003] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 01/13/2015] [Accepted: 03/04/2015] [Indexed: 01/08/2023]
Abstract
Identification of potential human Ether-a-go-go Related-Gene (hERG) potassium channel blockers is an essential part of the drug development and drug safety process in pharmaceutical industries or academic drug discovery centers, as they may lead to drug-induced QT prolongation, arrhythmia and Torsade de Pointes. Recent reports also suggest starting to address such issues at the hit selection stage. In order to prioritize molecules during the early drug discovery phase and to reduce the risk of drug attrition due to cardiotoxicity during pre-clinical and clinical stages, computational approaches have been developed to predict the potential hERG blockage of new drug candidates. In this review, we will describe the current in silico methods developed and applied to predict and to understand the mechanism of actions of hERG blockers, including ligand-based and structure-based approaches. We then discuss ongoing research on other ion channels and hERG polymorphism susceptible to be involved in LQTS and how systemic approaches can help in the drug safety decision.
Collapse
|
29
|
Obien MEJ, Deligkaris K, Bullmann T, Bakkum DJ, Frey U. Revealing neuronal function through microelectrode array recordings. Front Neurosci 2015; 8:423. [PMID: 25610364 PMCID: PMC4285113 DOI: 10.3389/fnins.2014.00423] [Citation(s) in RCA: 305] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 12/03/2014] [Indexed: 12/26/2022] Open
Abstract
Microelectrode arrays and microprobes have been widely utilized to measure neuronal activity, both in vitro and in vivo. The key advantage is the capability to record and stimulate neurons at multiple sites simultaneously. However, unlike the single-cell or single-channel resolution of intracellular recording, microelectrodes detect signals from all possible sources around every sensor. Here, we review the current understanding of microelectrode signals and the techniques for analyzing them. We introduce the ongoing advancements in microelectrode technology, with focus on achieving higher resolution and quality of recordings by means of monolithic integration with on-chip circuitry. We show how recent advanced microelectrode array measurement methods facilitate the understanding of single neurons as well as network function.
Collapse
Affiliation(s)
| | - Kosmas Deligkaris
- RIKEN Quantitative Biology Center, RIKEN Kobe, Japan ; Graduate School of Frontier Biosciences, Osaka University Osaka, Japan
| | | | - Douglas J Bakkum
- Department of Biosystems Science and Engineering, ETH Zurich Basel, Switzerland
| | - Urs Frey
- RIKEN Quantitative Biology Center, RIKEN Kobe, Japan ; Graduate School of Frontier Biosciences, Osaka University Osaka, Japan ; Department of Biosystems Science and Engineering, ETH Zurich Basel, Switzerland
| |
Collapse
|
30
|
Cooper J, Vik JO, Waltemath D. A call for virtual experiments: accelerating the scientific process. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2014; 117:99-106. [PMID: 25433232 DOI: 10.1016/j.pbiomolbio.2014.10.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 10/13/2014] [Indexed: 02/04/2023]
Abstract
Experimentation is fundamental to the scientific method, whether for exploration, description or explanation. We argue that promoting the reuse of virtual experiments (the in silico analogues of wet-lab or field experiments) would vastly improve the usefulness and relevance of computational models, encouraging critical scrutiny of models and serving as a common language between modellers and experimentalists. We review the benefits of reusable virtual experiments: in specifying, assaying, and comparing the behavioural repertoires of models; as prerequisites for reproducible research; to guide model reuse and composition; and for quality assurance in the translational application of models. A key step towards achieving this is that models and experimental protocols should be represented separately, but annotated so as to facilitate the linking of models to experiments and data. Lastly, we outline how the rigorous, streamlined confrontation between experimental datasets and candidate models would enable a "continuous integration" of biological knowledge, transforming our approach to systems biology.
Collapse
Affiliation(s)
- Jonathan Cooper
- Department of Computer Science, University of Oxford, Parks Road, Oxford OX1 3QD, UK.
| | - Jon Olav Vik
- Department of Animal and Aquacultural Sciences, Centre for Integrative Genetics, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway.
| | - Dagmar Waltemath
- Department of Systems Biology and Bioinformatics, University of Rostock, D-18051 Rostock, Germany.
| |
Collapse
|
31
|
Ryu H, Choi S, Park J, Yoo YE, Yoon JS, Seo YH, Kim YR, Kim SM, Jeon TJ. Automated Lipid Membrane Formation Using a Polydimethylsiloxane Film for Ion Channel Measurements. Anal Chem 2014; 86:8910-5. [DOI: 10.1021/ac501397t] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hyunil Ryu
- Department
of Biological Engineering, Inha University, Incheon, 402-751, South Korea
- Biohybrid
Systems Research Center (BSRC), Inha University, Incheon, 402-751, South Korea
| | - Sangbaek Choi
- Department
of Biological Engineering, Inha University, Incheon, 402-751, South Korea
- Biohybrid
Systems Research Center (BSRC), Inha University, Incheon, 402-751, South Korea
| | - Joongjin Park
- Department
of Biological Engineering, Inha University, Incheon, 402-751, South Korea
- Biohybrid
Systems Research Center (BSRC), Inha University, Incheon, 402-751, South Korea
| | - Yeong-Eun Yoo
- Nano-Mechanical
Systems Research Division, Korea Institute of Machinery and Materials, Daejeon, 305-343, South Korea
| | - Jae Sung Yoon
- Nano-Mechanical
Systems Research Division, Korea Institute of Machinery and Materials, Daejeon, 305-343, South Korea
| | - Young Ho Seo
- Department
of Mechanical and Mechatronics Engineering, Kangwon National University, Chuncheon, 200-701, South Korea
| | - Young-Rok Kim
- Institute
of Life Science and Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin, 472-864, South Korea
| | - Sun Min Kim
- Biohybrid
Systems Research Center (BSRC), Inha University, Incheon, 402-751, South Korea
- Department
of Mechanical Engineering, Inha University, Incheon, 402-751, Republic of Korea
| | - Tae-Joon Jeon
- Department
of Biological Engineering, Inha University, Incheon, 402-751, South Korea
- Biohybrid
Systems Research Center (BSRC), Inha University, Incheon, 402-751, South Korea
| |
Collapse
|
32
|
Bruhn BR, Liu H, Schuhladen S, Hunt AJ, Mordovanakis A, Mayer M. Dual-pore glass chips for cell-attached single-channel recordings. LAB ON A CHIP 2014; 14:2410-7. [PMID: 24844315 PMCID: PMC4121072 DOI: 10.1039/c4lc00370e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
While high-throughput planar patch-clamp instruments are now established to perform whole-cell recordings for drug screening, the conventional micropipette-based approach remains the gold standard for performing cell-attached single-channel recordings. Generally, planar platforms are not well-suited for such studies due to excess noise resulting from low seal resistances and the use of substrates with poor dielectric properties. Since these platforms tend to use the same pore to position a cell by suction and establish a seal, biological debris from the cell suspension can contaminate the pore surface prior to seal formation, reducing the seal resistance. Here, femtosecond laser ablation was used to fabricate dual-pore glass chips optimized for use in cell-attached single-channel recordings that circumvent this problem by using different pores to position a cell and to establish a seal. This dual-pore design also permitted the use of a relatively small patch aperture (D ~ 150 to 300 nm) that is better-suited for establishing high-resistance seals than the micropores used typically in planar patch-clamp setups (D ~ 1 to 2 μm) without compromising the ability of the device to position a cell. Taking advantage of the high seal resistances and low capacitive and dielectric noise realized using glass substrates, patch-clamp experiments with these dual-pore chips consistently achieved high seal resistances (rate of gigaseal formation = 61%, mean seal resistance = 53 GΩ), maintained gigaseals for prolonged durations (up to 6 hours), achieved RMS noise values as low as 0.46 pA at 5 kHz bandwidth, and enabled single-channel recordings in the cell-attached configuration that are comparable to those obtained by conventional patch-clamp.
Collapse
Affiliation(s)
- Brandon R Bruhn
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
| | | | | | | | | | | |
Collapse
|
33
|
Label-free cell phenotypic profiling decodes the composition and signaling of an endogenous ATP-sensitive potassium channel. Sci Rep 2014; 4:4934. [PMID: 24816792 PMCID: PMC4017216 DOI: 10.1038/srep04934] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 04/24/2014] [Indexed: 11/27/2022] Open
Abstract
Current technologies for studying ion channels are fundamentally limited because of their inability to functionally link ion channel activity to cellular pathways. Herein, we report the use of label-free cell phenotypic profiling to decode the composition and signaling of an endogenous ATP-sensitive potassium ion channel (KATP) in HepG2C3A, a hepatocellular carcinoma cell line. Label-free cell phenotypic agonist profiling showed that pinacidil triggered characteristically similar dynamic mass redistribution (DMR) signals in A431, A549, HT29 and HepG2C3A, but not in HepG2 cells. Reverse transcriptase PCR, RNAi knockdown, and KATP blocker profiling showed that the pinacidil DMR is due to the activation of SUR2/Kir6.2 KATP channels in HepG2C3A cells. Kinase inhibition and RNAi knockdown showed that the pinacidil activated KATP channels trigger signaling through Rho kinase and Janus kinase-3, and cause actin remodeling. The results are the first demonstration of a label-free methodology to characterize the composition and signaling of an endogenous ATP-sensitive potassium ion channel.
Collapse
|
34
|
Stava E, Shin HC, Yu M, Bhat A, Resto P, Seshadri A, Williams JC, Blick RH. Ultra-stable glass microcraters for on-chip patch clamping. RSC Adv 2014. [DOI: 10.1039/c4ra04978k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Dual-sided laser ablation is used to form glass microcraters commensurate with the size of a cell. These microcraters allow for ultra-stable, low noise recordings of planar patch-clamped cells.
Collapse
Affiliation(s)
- Eric Stava
- Institut für Angewandte Physik
- Universität Hamburg
- 20355 Hamburg, Germany
- Department of Electrical and Computer Engineering
- University of Wisconsin–Madison
| | - Hyun Cheol Shin
- Materials Science Program
- University of Wisconsin–Madison
- Madison, USA
| | - Minrui Yu
- Department of Electrical and Computer Engineering
- University of Wisconsin–Madison
- Madison, USA
| | - Abhishek Bhat
- Department of Electrical and Computer Engineering
- University of Wisconsin–Madison
- Madison, USA
| | - Pedro Resto
- Department of Biomedical Engineering
- University of Wisconsin–Madison
- Madison, USA
- Mechanical Engineering Department
- University of Puerto Rico at Mayagüez
| | - Arjun Seshadri
- Department of Electrical and Computer Engineering
- University of Wisconsin–Madison
- Madison, USA
| | - Justin C. Williams
- Materials Science Program
- University of Wisconsin–Madison
- Madison, USA
- Department of Biomedical Engineering
- University of Wisconsin–Madison
| | - Robert H. Blick
- Institut für Angewandte Physik
- Universität Hamburg
- 20355 Hamburg, Germany
- Department of Electrical and Computer Engineering
- University of Wisconsin–Madison
| |
Collapse
|
35
|
Abstract
Computer-aided drug discovery/design methods have played a major role in the development of therapeutically important small molecules for over three decades. These methods are broadly classified as either structure-based or ligand-based methods. Structure-based methods are in principle analogous to high-throughput screening in that both target and ligand structure information is imperative. Structure-based approaches include ligand docking, pharmacophore, and ligand design methods. The article discusses theory behind the most important methods and recent successful applications. Ligand-based methods use only ligand information for predicting activity depending on its similarity/dissimilarity to previously known active ligands. We review widely used ligand-based methods such as ligand-based pharmacophores, molecular descriptors, and quantitative structure-activity relationships. In addition, important tools such as target/ligand data bases, homology modeling, ligand fingerprint methods, etc., necessary for successful implementation of various computer-aided drug discovery/design methods in a drug discovery campaign are discussed. Finally, computational methods for toxicity prediction and optimization for favorable physiologic properties are discussed with successful examples from literature.
Collapse
Affiliation(s)
- Gregory Sliwoski
- Jr., Center for Structural Biology, 465 21st Ave South, BIOSCI/MRBIII, Room 5144A, Nashville, TN 37232-8725.
| | | | | | | |
Collapse
|
36
|
Tanzi S, Matteucci M, Christiansen TL, Friis S, Christensen MT, Garnaes J, Wilson S, Kutchinsky J, Taboryski R. Ion channel recordings on an injection-molded polymer chip. LAB ON A CHIP 2013; 13:4784-4793. [PMID: 24154831 DOI: 10.1039/c3lc50760b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this paper, we demonstrate recordings of the ion channel activity across the cell membrane in a biological cell by employing the so-called patch clamping technique on an injection-molded polymer microfluidic device. The findings will allow direct recordings of ion channel activity to be made using the cheapest materials and production platform to date and with the potential for very high throughput. The employment of cornered apertures for cell capture allowed the fabrication of devices without through holes and via a scheme comprising master origination by dry etching in a silicon substrate, electroplating in nickel and injection molding of the final part. The most critical device parameters were identified as the length of the patching capillary and the very low surface roughness on the inside of the capillary. The cross-sectional shape of the orifice was found to be less critical, as both rectangular and semicircular profiles seemed to have almost the same ability to form tight seals with cells with negligible leak currents. The devices were functionally tested using human embryonic kidney cells expressing voltage-gated sodium channels (Nav1.7) and benchmarked against a commercial state-of-the-art system for automated ion channel recordings. These experiments considered current-voltage (IV) relationships for activation and inactivation of the Nav1.7 channels and their sensitivity to a local anesthetic, lidocaine. Both IVs and lidocaine dose-response curves obtained from the injection-molded polymer device were in good agreement with data obtained from the commercial system.
Collapse
Affiliation(s)
- Simone Tanzi
- Department of Micro- and Nanotechnology, Technical University of Denmark, Building 345E, DK-2800 Kongens Lyngby, Denmark.
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Rosenstein JK, Ramakrishnan S, Roseman J, Shepard KL. Single ion channel recordings with CMOS-anchored lipid membranes. NANO LETTERS 2013; 13:2682-6. [PMID: 23634707 PMCID: PMC3683112 DOI: 10.1021/nl400822r] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We present single-ion-channel recordings performed with biomimetic lipid membranes which are directly attached to the surface of a complementary metal-oxide-semiconductor (CMOS) preamplifier chip. With this system we resolve single-channel currents from several types of bacterial ion channels, including fluctuations of a single alamethicin channel at a bandwidth of 1 MHz which represent the fastest single-ion-channel recordings reported to date. The platform is also used for high-resolution α-hemolysin nanopore recordings. These results illustrate the high signal fidelity, fine temporal resolution, small geometry, and multiplexed integration which can be achieved by leveraging integrated semiconductor platforms for advanced ion channel interfaces.
Collapse
Affiliation(s)
- Jacob K Rosenstein
- Department of Electrical Engineering, Columbia University, New York, New York 10027, USA.
| | | | | | | |
Collapse
|
38
|
Elkins RC, Davies MR, Brough SJ, Gavaghan DJ, Cui Y, Abi-Gerges N, Mirams GR. Variability in high-throughput ion-channel screening data and consequences for cardiac safety assessment. J Pharmacol Toxicol Methods 2013; 68:112-22. [PMID: 23651875 PMCID: PMC4135079 DOI: 10.1016/j.vascn.2013.04.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 04/05/2013] [Accepted: 04/25/2013] [Indexed: 11/29/2022]
Abstract
Introduction Unwanted drug interactions with ionic currents in the heart can lead to an increased proarrhythmic risk to patients in the clinic. It is therefore a priority for safety pharmacology teams to detect block of cardiac ion channels, and new technologies have enabled the development of automated and high-throughput screening assays using cell lines. As a result of screening multiple ion-channels there is a need to integrate information, particularly for compounds affecting more than one current, and mathematical electrophysiology in-silico action potential models are beginning to be used for this. Methods We quantified the variability associated with concentration-effect curves fitted to recordings from high-throughput Molecular Devices IonWorks® Quattro™ screens when detecting block of IKr (hERG), INa (NaV1.5), ICaL (CaV1.2), IKs (KCNQ1/minK) and Ito (Kv4.3/KChIP2.2), and the Molecular Devices FLIPR® Tetra fluorescence screen for ICaL (CaV1.2), for control compounds used at AstraZeneca and GlaxoSmithKline. We examined how screening variability propagates through in-silico action potential models for whole cell electrical behaviour, and how confidence intervals on model predictions can be estimated with repeated simulations. Results There are significant levels of variability associated with high-throughput ion channel electrophysiology screens. This variability is of a similar magnitude for different cardiac ion currents and different compounds. Uncertainty in the Hill coefficients of reported concentration-effect curves is particularly high. Depending on a compound’s ion channel blocking profile, the uncertainty introduced into whole-cell predictions can become significant. Discussion Our technique allows confidence intervals to be placed on computational model predictions that are based on high-throughput ion channel screens. This allows us to suggest when repeated screens should be performed to reduce uncertainty in a compound’s action to acceptable levels, to allow a meaningful interpretation of the data.
Collapse
Affiliation(s)
- Ryan C Elkins
- Global Safety Pharmacology, Global Safety Assessment, AstraZeneca, Alderley Park SK10 4TG, UK
| | | | | | | | | | | | | |
Collapse
|
39
|
Park JW, Kim HJ, Kang MW, Jeon NL. Advances in microfluidics-based experimental methods for neuroscience research. LAB ON A CHIP 2013; 13:509-521. [PMID: 23306275 DOI: 10.1039/c2lc41081h] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The application of microfluidics to neuroscience applications has always appealed to neuroscientists because of the capability to control the cellular microenvironment in both a spatial and temporal manner. Recently, there has been rapid development of biological micro-electro-mechanical systems (BioMEMS) for both fundamental and applied neuroscience research. In this review, we will discuss the applications of BioMEMS to various topics in the field of neuroscience. The purpose of this review is to summarise recent advances in the components and design of the BioMEMS devices, in vitro disease models, electrophysiology and neural stem cell research. We envision that microfluidics will play a key role in future neuroscience research, both fundamental and applied research.
Collapse
Affiliation(s)
- Jae Woo Park
- Division of WCU (World Class University) Multiscale Mechanical Design, School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, Korea
| | | | | | | |
Collapse
|
40
|
Yajuan X, Xin L, Zhiyuan L. A comparison of the performance and application differences between manual and automated patch-clamp techniques. CURRENT CHEMICAL GENOMICS 2012; 6:87-92. [PMID: 23346269 PMCID: PMC3549544 DOI: 10.2174/1875397301206010087] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 06/29/2012] [Accepted: 11/05/2012] [Indexed: 11/22/2022]
Abstract
The patch clamp technique is commonly used in electrophysiological experiments and offers direct insight into ion channel properties through the characterization of ion channel activity. This technique can be used to elucidate the interaction between a drug and a specific ion channel at different conformational states to understand the ion channel modulators' mechanisms. The patch clamp technique is regarded as a gold standard for ion channel research; however, it suffers from low throughput and high personnel costs. In the last decade, the development of several automated electrophysiology platforms has greatly increased the screen throughput of whole cell electrophysiological recordings. New advancements in the automated patch clamp systems have aimed to provide high data quality, high content, and high throughput. However, due to the limitations noted above, automated patch clamp systems are not capable of replacing manual patch clamp systems in ion channel research. While automated patch clamp systems are useful for screening large amounts of compounds in cell lines that stably express high levels of ion channels, the manual patch clamp technique is still necessary for studying ion channel properties in some research areas and for specific cell types, including primary cells that have mixed cell types and differentiated cells that derive from induced pluripotent stem cells (iPSCs) or embryonic stem cells (ESCs). Therefore, further improvements in flexibility with regard to cell types and data quality will broaden the applications of the automated patch clamp systems in both academia and industry.
Collapse
Affiliation(s)
- Xiao Yajuan
- Key Laboratory of Regenerative Biology, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | | | | |
Collapse
|
41
|
Overview of micro- and nano-technology tools for stem cell applications: micropatterned and microelectronic devices. SENSORS 2012. [PMID: 23202240 PMCID: PMC3522993 DOI: 10.3390/s121115947] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
In the past few decades the scientific community has been recognizing the paramount role of the cell microenvironment in determining cell behavior. In parallel, the study of human stem cells for their potential therapeutic applications has been progressing constantly. The use of advanced technologies, enabling one to mimic the in vivo stem cell microenviroment and to study stem cell physiology and physio-pathology, in settings that better predict human cell biology, is becoming the object of much research effort. In this review we will detail the most relevant and recent advances in the field of biosensors and micro- and nano-technologies in general, highlighting advantages and disadvantages. Particular attention will be devoted to those applications employing stem cells as a sensing element.
Collapse
|
42
|
Abstract
Lipid bilayers are natural barriers of biological cells and cellular compartments. Membrane proteins integrated in biological membranes enable vital cell functions such as signal transduction and the transport of ions or small molecules. In order to determine the activity of a protein of interest at defined conditions, the membrane protein has to be integrated into artificial lipid bilayers immobilized on a surface. For the fabrication of such biosensors expertise is required in material science, surface and analytical chemistry, molecular biology and biotechnology. Specifically, techniques are needed for structuring surfaces in the micro- and nanometer scale, chemical modification and analysis, lipid bilayer formation, protein expression, purification and solubilization, and most importantly, protein integration into engineered lipid bilayers. Electrochemical and optical methods are suitable to detect membrane activity-related signals. The importance of structural knowledge to understand membrane protein function is obvious. Presently only a few structures of membrane proteins are solved at atomic resolution. Functional assays together with known structures of individual membrane proteins will contribute to a better understanding of vital biological processes occurring at biological membranes. Such assays will be utilized in the discovery of drugs, since membrane proteins are major drug targets.
Collapse
|
43
|
de Courcey F, Zholos AV, Atherton-Watson H, Williams MTS, Canning P, Danahay HL, Elborn JS, Ennis M. Development of primary human nasal epithelial cell cultures for the study of cystic fibrosis pathophysiology. Am J Physiol Cell Physiol 2012; 303:C1173-9. [PMID: 23015550 DOI: 10.1152/ajpcell.00384.2011] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Cultured primary epithelial cells are used to examine inflammation in cystic fibrosis (CF). We describe a new human model system using cultured nasal brushings. Nasal brushings were obtained from 16 F508del homozygous patients and 11 healthy controls. Cells were resuspended in airway epithelial growth medium and seeded onto collagen-coated flasks and membranes for use in patch-clamp, ion transport, and mediator release assays. Viable cultures were obtained with a 75% success rate from subjects with CF and 100% from control subjects. Amiloride-sensitive epithelial Na channel current of similar size was present in both cell types while forskolin-activated CF transmembrane conductance regulator current was lacking in CF cells. In Ussing chambers, cells from CF patients responded to UTP but not to forskolin. Spontaneous and cytomix-stimulated IL-8 release was similar (stimulated 29,448 ± 9,025 pg/ml; control 16,336 ± 3,308 pg/ml CF; means ± SE). Thus nasal epithelial cells from patients with CF can be grown from nasal brushings and used in electrophysiological and mediator release studies in CF research.
Collapse
Affiliation(s)
- F de Courcey
- Centre for Infection and Immunity, Queen’s University Belfast, Health Sciences Building, Belfast, UK
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Spencer CI, Li N, Chen Q, Johnson J, Nevill T, Kammonen J, Ionescu-Zanetti C. Ion channel pharmacology under flow: automation via well-plate microfluidics. Assay Drug Dev Technol 2012; 10:313-24. [PMID: 22574656 DOI: 10.1089/adt.2011.414] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Automated patch clamping addresses the need for high-throughput screening of chemical entities that alter ion channel function. As a result, there is considerable utility in the pharmaceutical screening arena for novel platforms that can produce relevant data both rapidly and consistently. Here we present results that were obtained with an innovative microfluidic automated patch clamp system utilizing a well-plate that eliminates the necessity of internal robotic liquid handling. Continuous recording from cell ensembles, rapid solution switching, and a bench-top footprint enable a number of assay formats previously inaccessible to automated systems. An electro-pneumatic interface was employed to drive the laminar flow of solutions in a microfluidic network that delivered cells in suspension to ensemble recording sites. Whole-cell voltage clamp was applied to linear arrays of 20 cells in parallel utilizing a 64-channel voltage clamp amplifier. A number of unique assays requiring sequential compound applications separated by a second or less, such as rapid determination of the agonist EC(50) for a ligand-gated ion channel or the kinetics of desensitization recovery, are enabled by the system. In addition, the system was validated via electrophysiological characterizations of both voltage-gated and ligand-gated ion channel targets: hK(V)2.1 and human Ether-à-go-go-related gene potassium channels, hNa(V)1.7 and 1.8 sodium channels, and (α1) hGABA(A) and (α1) human nicotinic acetylcholine receptor receptors. Our results show that the voltage dependence, kinetics, and interactions of these channels with pharmacological agents were matched to reference data. The results from these IonFlux™ experiments demonstrate that the system provides high-throughput automated electrophysiology with enhanced reliability and consistency, in a user-friendly format.
Collapse
Affiliation(s)
- C Ian Spencer
- Fluxion Biosciences, Inc., South San Francisco, California 94080, USA
| | | | | | | | | | | | | |
Collapse
|
45
|
Goldstein B, Kim D, Xu J, Vanderlick TK, Culurciello E. CMOS low current measurement system for biomedical applications. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2012; 6:111-119. [PMID: 23852976 DOI: 10.1109/tbcas.2011.2182512] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We present a micro-chip implementation of a low current measurement system for biomedical applications using capacitive feedback that exhibits 190 fA of RMS noise in a 1 kHz bandwidth. The sampling rate is selectable up to 100 kHz. When measuring the amplifier noise with a 10 GΩ resistor and a 47 pF capacitor at the input, typical of cell membrane capacitance in DNA and patch clamp experiments, the measured RMS noise was 2.44 pA on a 50 pA signal in a 10 kHz bandwidth. Two channels were implemented on 630 × 440 μm² using a 0.5-μm 3-metal 2-poly CMOS process. Each channel consumes 1.5 mW of power from a 3.3 V supply. We measured the characteristics of an artificial lipid bilayer similar to the ones used in DNA sequencing experiments via nanopores.
Collapse
Affiliation(s)
- Brian Goldstein
- Department of Electrical Engineering, Yale University, New Haven, CT 06520, USA.
| | | | | | | | | |
Collapse
|
46
|
Zagnoni M. Miniaturised technologies for the development of artificial lipid bilayer systems. LAB ON A CHIP 2012; 12:1026-1039. [PMID: 22301684 DOI: 10.1039/c2lc20991h] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Artificially reproducing cellular environments is a key aim of synthetic biology, which has the potential to greatly enhance our understanding of cellular mechanisms. Microfluidic and lab-on-a-chip (LOC) techniques, which enable the controlled handling of sub-microlitre volumes of fluids in an automated and high-throughput manner, can play a major role in achieving this by offering alternative and powerful methodologies in an on-chip format. Such techniques have been successfully employed over the last twenty years to provide innovative solutions for chemical analysis and cell-, molecular- and synthetic- biology. In the context of the latter, the formation of artificial cell membranes (or artificial lipid bilayers) that incorporate membrane proteins within miniaturised LOC architectures offers huge potential for the development of highly sensitive molecular sensors and drug screening applications. The aim of this review is to give a comprehensive and critical overview of the field of microsystems for creating and exploiting artificial lipid bilayers. Advantages and limitations of three of the most popular approaches, namely suspended, supported and droplet-based lipid bilayers, are discussed. Examples are reported that show how artificial cell membrane microsystems, by combining together biological procedures and engineering techniques, can provide novel methodologies for basic biological and biophysical research and for the development of biotechnology tools.
Collapse
Affiliation(s)
- Michele Zagnoni
- Centre for Microsystems and Photonics, University of Strathclyde, Glasgow, UK.
| |
Collapse
|
47
|
Li X, Li PCH. Strategies for the real-time detection of Ca2+ channel events of single cells: recent advances and new possibilities. Expert Rev Clin Pharmacol 2012; 3:267-80. [PMID: 22111609 DOI: 10.1586/ecp.10.16] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Ca(2+) ion channels play key roles in cell physiology and they are important drug targets. The Ca(2+) channel events are mainly measurable by fluorescent and patch clamp methods. This review summarizes the recent advances of these techniques for the detection of Ca(2+) channel events and the prospect of their new directions in the near future. Conventional bulk fluorescent methods are amenable to high-throughput applications, but they are not real-time single-cell measurements, which provide kinetic data on individual cells and offer unparalleled sensitive data for rare cells. Recent advances on real-time single-cell fluorescent measurements are conducted on microfluidic chips with scalable cell-retention sites, integrated with electrical stimulation and fluorescent measuring features. Patch clamp techniques are real-time measurements conducted on single cells, but the measurements are of low throughput. Recent advances are conducted on microfluidic patch clamp chips for high-throughput applications. Future real-time single-cell Ca(2+) channel event measurements will be conducted in a multiparametric manner in an integrated and automated microfluidic chip.
Collapse
Affiliation(s)
- XiuJun Li
- University of California at Berkeley, CA 94720, USA
| | | |
Collapse
|
48
|
Experimental chemotherapy and approaches to drug discovery for Trypanosoma cruzi infection. ADVANCES IN PARASITOLOGY 2011; 75:89-119. [PMID: 21820553 DOI: 10.1016/b978-0-12-385863-4.00005-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In the 100 years since the discovery of Chagas disease, only two drugs have been developed and introduced into clinical practice, and these drugs were introduced over 40 years ago. The tools of drug discovery have improved dramatically in the interim; however, this has not translated into new drugs for Chagas disease. This has been largely because the main practitioners of drug discovery are pharmaceutical companies who are not financially motivated to invest in Chagas disease and other "orphan" diseases. As a result, it has largely been up to academic groups to bring drug candidates through the discovery pipeline and to clinical trials. The difficulty with drug discovery in academia has been the challenge of bringing together the diverse expertise in biology, chemistry, and pharmacology in concerted efforts towards a common goal of developing therapeutics. Funding is often inadequate, but lack of coordination amongst academic investigators with different expertise has also contributed to the slow progress. The purpose of this chapter is to provide an overview of approaches that can be accomplished in academic settings for preclinical drug discovery for Chagas disease. The chapter addresses methods of drug screening against Trypanosoma cruzi cultures and in animal models and includes general topics on compound selection, testing for drug-like properties (including oral bioavailability), investigating the pharmacokinetics and toxicity of compounds, and finally providing parameters to help with triaging compounds.
Collapse
|
49
|
Kraushaar U, Meyer T, Hess D, Gepstein L, L Mummery C, R Braam S, Guenther E. Cardiac safety pharmacology: from human ether-a-gogo related gene channel block towards induced pluripotent stem cell based disease models. Expert Opin Drug Saf 2011; 11:285-98. [DOI: 10.1517/14740338.2012.639358] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
50
|
Jung SH, Choi S, Kim YR, Jeon TJ. Storable droplet interface lipid bilayers for cell-free ion channel studies. Bioprocess Biosyst Eng 2011; 35:241-6. [PMID: 21909672 DOI: 10.1007/s00449-011-0602-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Accepted: 07/16/2011] [Indexed: 11/24/2022]
Abstract
An artificially created lipid bilayer is an important platform in studying ion channels and engineered biosensor applications. However, a lipid bilayer created using conventional techniques is fragile and short-lived, and the measurement of ion channels requires expertise and laborious procedures, precluding practical applications. Here, we demonstrate a storable droplet lipid bilayer precursor frozen with ion channels, resulting in a droplet interface bilayer upon thawing. A small vial with an aqueous droplet in organic solution was flash frozen in -80 °C methanol immediately after an aqueous droplet was introduced into the organic solution and gravity draws the droplet down to the interface upon thawing. A lipid bilayer created along the interface using this method had giga-ohm resistance and typical specific capacitance values. The noise level of this system is favorably comparable to the conventional system. The subsequent incorporation of ion channels, alpha-hemolysin and gramicidin A, showed typical conductance values consistent with those in previous literatures. This novel system to create a lipid bilayer as a whole can be automated from its manufacture to use and indefinitely stored when frozen. As a result, ion channel measurements can be carried out in any place, increasing the accessibility of ion channel studies as well as a number of applications, such as biosensors, ion channel drug screening, and biophysical studies.
Collapse
Affiliation(s)
- Sung-Ho Jung
- Department of Biological Engineering, Inha University, Incheon, Korea
| | | | | | | |
Collapse
|