1
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Li L, Hernandez CC, Gimenez LE, Xu B, Dahir NS, Swati, Birnbaum SG, Cone RD, Liu C. Functional coupling between MC4R and Kir7.1 contributes to clozapine-induced hyperphagia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.07.597973. [PMID: 38895206 PMCID: PMC11185771 DOI: 10.1101/2024.06.07.597973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Most antipsychotic drugs (APDs) induce hyperphagia and weight gain. However, the neural mechanisms are poorly understood, partly due to challenges replicating their metabolic effects in rodents. Here, we report a new mouse model that recapitulates overeating induced by clozapine, a widely prescribed APD. Our study shows that clozapine boosts food intake by inhibiting melanocortin 4 receptor (MC4R) expressing neurons in the paraventricular nucleus of the hypothalamus. Interestingly, neither clozapine nor risperidone, another commonly used APD, affects receptor-ligand binding or the canonical Gαs signaling of MC4R. Instead, they inhibit neuronal activity by enhancing the coupling between MC4R and Kir7.1, leading to the open state of the inwardly rectifying potassium channel. Deletion of Kir7.1 in Mc4r-Cre neurons prevents clozapine-induced weight gain, while treatment with a selective Kir7.1 blocker mitigates overeating in clozapine-fed mice. Our findings unveil a molecular pathway underlying the effect of APDs on feeding behavior and suggest its potential as a therapeutic target.
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Campàs M, Reverté J, Tudó À, Alkassar M, Diogène J, Sureda FX. Automated Patch Clamp for the Detection of Tetrodotoxin in Pufferfish Samples. Mar Drugs 2024; 22:176. [PMID: 38667793 PMCID: PMC11050952 DOI: 10.3390/md22040176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 04/10/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
Tetrodotoxin (TTX) is a marine toxin responsible for many intoxications around the world. Its presence in some pufferfish species and, as recently reported, in shellfish, poses a serious health concern. Although TTX is not routinely monitored, there is a need for fast, sensitive, reliable, and simple methods for its detection and quantification. In this work, we describe the use of an automated patch clamp (APC) system with Neuro-2a cells for the determination of TTX contents in pufferfish samples. The cells showed an IC50 of 6.4 nM for TTX and were not affected by the presence of muscle, skin, liver, and gonad tissues of a Sphoeroides pachygaster specimen (TTX-free) when analysed at 10 mg/mL. The LOD achieved with this technique was 0.05 mg TTX equiv./kg, which is far below the Japanese regulatory limit of 2 mg TTX equiv./kg. The APC system was applied to the analysis of extracts of a Lagocephalus sceleratus specimen, showing TTX contents that followed the trend of gonads > liver > skin > muscle. The APC system, providing an in vitro toxicological approach, offers the advantages of being sensitive, rapid, and reliable for the detection of TTX-like compounds in seafood.
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Affiliation(s)
- Mònica Campàs
- IRTA, Marine and Continental Waters (AMiC) Programme, Ctra. Poble Nou del Delta, km. 5.5, 43540 La Ràpita, Spain; (J.R.); (M.A.); (J.D.)
| | - Jaume Reverté
- IRTA, Marine and Continental Waters (AMiC) Programme, Ctra. Poble Nou del Delta, km. 5.5, 43540 La Ràpita, Spain; (J.R.); (M.A.); (J.D.)
- Department of Basic Medical Sciences, Universitat Rovira i Virgili, C/Sant Llorenç 21, 43201 Reus, Spain;
| | - Àngels Tudó
- Department of Basic Medical Sciences, Universitat Rovira i Virgili, C/Sant Llorenç 21, 43201 Reus, Spain;
| | - Mounira Alkassar
- IRTA, Marine and Continental Waters (AMiC) Programme, Ctra. Poble Nou del Delta, km. 5.5, 43540 La Ràpita, Spain; (J.R.); (M.A.); (J.D.)
- Department of Basic Medical Sciences, Universitat Rovira i Virgili, C/Sant Llorenç 21, 43201 Reus, Spain;
| | - Jorge Diogène
- IRTA, Marine and Continental Waters (AMiC) Programme, Ctra. Poble Nou del Delta, km. 5.5, 43540 La Ràpita, Spain; (J.R.); (M.A.); (J.D.)
| | - Francesc X. Sureda
- Department of Basic Medical Sciences, Universitat Rovira i Virgili, C/Sant Llorenç 21, 43201 Reus, Spain;
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Gimenez LE, Martin C, Yu J, Hollanders C, Hernandez CC, Wu Y, Yao D, Han GW, Dahir NS, Wu L, Van der Poorten O, Lamouroux A, Mannes M, Zhao S, Tourwé D, Stevens RC, Cone RD, Ballet S. Novel Cocrystal Structures of Peptide Antagonists Bound to the Human Melanocortin Receptor 4 Unveil Unexplored Grounds for Structure-Based Drug Design. J Med Chem 2024; 67:2690-2711. [PMID: 38345933 DOI: 10.1021/acs.jmedchem.3c01822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Melanocortin 4 receptor (MC4-R) antagonists are actively sought for treating cancer cachexia. We determined the structures of complexes with PG-934 and SBL-MC-31. These peptides differ from SHU9119 by substituting His6 with Pro6 and inserting Gly10 or Arg10. The structures revealed two subpockets at the TM7-TM1-TM2 domains, separated by N2857.36. Two peptide series based on the complexed peptides led to an antagonist activity and selectivity SAR study. Most ligands retained the SHU9119 potency, but several SBL-MC-31-derived peptides significantly enhanced MC4-R selectivity over MC1-R by 60- to 132-fold. We also investigated MC4-R coupling to the K+ channel, Kir7.1. Some peptides activated the channel, whereas others induced channel closure independently of G protein coupling. In cell culture studies, channel activation correlated with increased feeding, while a peptide with Kir7.1 inhibitory activity reduced eating. These results highlight the potential for targeting the MC4-R:Kir7.1 complex for treating positive and restrictive eating disorders.
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Affiliation(s)
- Luis E Gimenez
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Charlotte Martin
- Research Group of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, Brussels B-1050, Belgium
| | - Jing Yu
- iHuman Institute, ShanghaiTech University, Ren Building, 393 Middle Huaxia Road, Pudong, Shanghai 201210, China
| | - Charlie Hollanders
- Research Group of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, Brussels B-1050, Belgium
| | - Ciria C Hernandez
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Yiran Wu
- iHuman Institute, ShanghaiTech University, Ren Building, 393 Middle Huaxia Road, Pudong, Shanghai 201210, China
| | - Deqiang Yao
- iHuman Institute, ShanghaiTech University, Ren Building, 393 Middle Huaxia Road, Pudong, Shanghai 201210, China
| | - Gye Won Han
- Departments of Biological Sciences and Chemistry, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, California 90089, United States
| | - Naima S Dahir
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Molecular and Integrative Physiology, School of Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Lijie Wu
- iHuman Institute, ShanghaiTech University, Ren Building, 393 Middle Huaxia Road, Pudong, Shanghai 201210, China
| | - Olivier Van der Poorten
- Research Group of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, Brussels B-1050, Belgium
| | - Arthur Lamouroux
- Research Group of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, Brussels B-1050, Belgium
| | - Morgane Mannes
- Research Group of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, Brussels B-1050, Belgium
| | - Suwen Zhao
- iHuman Institute, ShanghaiTech University, Ren Building, 393 Middle Huaxia Road, Pudong, Shanghai 201210, China
| | - Dirk Tourwé
- Research Group of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, Brussels B-1050, Belgium
| | - Raymond C Stevens
- iHuman Institute, ShanghaiTech University, Ren Building, 393 Middle Huaxia Road, Pudong, Shanghai 201210, China
| | - Roger D Cone
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Molecular and Integrative Physiology, School of Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Molecular, Cellular, and Developmental Biology, College of Literature, Science, and the Arts, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Steven Ballet
- Research Group of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, Brussels B-1050, Belgium
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Hernandez CC, Hu N, Shen W, Macdonald RL. Epileptic Encephalopathy GABRB Structural Variants Share Common Gating and Trafficking Defects. Biomolecules 2023; 13:1790. [PMID: 38136660 PMCID: PMC10741827 DOI: 10.3390/biom13121790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 12/08/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Variants in the GABRB gene, which encodes the β subunit of the GABAA receptor, have been implicated in various epileptic encephalopathies and related neurodevelopmental disorders such as Dravet syndrome and Angelman syndrome. These conditions are often associated with early-onset seizures, developmental regression, and cognitive impairments. The severity and specific features of these encephalopathies can differ based on the nature of the genetic variant and its impact on GABAA receptor function. These variants can lead to dysfunction in GABAA receptor-mediated inhibition, resulting in an imbalance between neuronal excitation and inhibition that contributes to the development of seizures. Here, 13 de novo EE-associated GABRB variants, occurring as missense mutations, were analyzed to determine their impact on protein stability and flexibility, channel function, and receptor biogenesis. Our results showed that all mutations studied significantly impact the protein structure, altering protein stability, flexibility, and function to varying degrees. Variants mapped to the GABA-binding domain, coupling zone, and pore domain significantly impact the protein structure, modifying the β+/α- interface of the receptor and altering channel activation and receptor trafficking. Our study proposes that the extent of loss or gain of GABAA receptor function can be elucidated by identifying the specific structural domain impacted by mutation and assessing the variability in receptor structural dynamics. This paves the way for future studies to explore and uncover links between the incidence of a variant in the receptor topology and the severity of the related disease.
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Affiliation(s)
- Ciria C. Hernandez
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ningning Hu
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; (N.H.); (W.S.); (R.L.M.)
| | - Wangzhen Shen
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; (N.H.); (W.S.); (R.L.M.)
| | - Robert L. Macdonald
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; (N.H.); (W.S.); (R.L.M.)
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5
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Hernandez CC, Shen Y, Hu N, Shen W, Narayanan V, Ramsey K, He W, Zou L, Macdonald RL. GABRG2 Variants Associated with Febrile Seizures. Biomolecules 2023; 13:414. [PMID: 36979350 PMCID: PMC10046037 DOI: 10.3390/biom13030414] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 02/13/2023] [Accepted: 02/17/2023] [Indexed: 02/24/2023] Open
Abstract
Febrile seizures (FS) are the most common form of epilepsy in children between six months and five years of age. FS is a self-limited type of fever-related seizure. However, complicated prolonged FS can lead to complex partial epilepsy. We found that among the GABAA receptor subunit (GABR) genes, most variants associated with FS are harbored in the γ2 subunit (GABRG2). Here, we characterized the effects of eight variants in the GABAA receptor γ2 subunit on receptor biogenesis and channel function. Two-thirds of the GABRG2 variants followed the expected autosomal dominant inheritance in FS and occurred as missense and nonsense variants. The remaining one-third appeared as de novo in the affected probands and occurred only as missense variants. The loss of GABAA receptor function and dominant negative effect on GABAA receptor biogenesis likely caused the FS phenotype. In general, variants in the GABRG2 result in a broad spectrum of phenotypic severity, ranging from asymptomatic, FS, genetic epilepsy with febrile seizures plus (GEFS+), and Dravet syndrome individuals. The data presented here support the link between FS, epilepsy, and GABRG2 variants, shedding light on the relationship between the variant topological occurrence and disease severity.
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Affiliation(s)
- Ciria C. Hernandez
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yanwen Shen
- Department of Pediatrics, Seventh Medical Center of Chinese PLA General Hospital, Beijing 100010, China
| | - Ningning Hu
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Wangzhen Shen
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Vinodh Narayanan
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ 85004, USA
| | - Keri Ramsey
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ 85004, USA
| | - Wen He
- Department of Pediatrics, Seventh Medical Center of Chinese PLA General Hospital, Beijing 100010, China
| | - Liping Zou
- Department of Pediatrics, Seventh Medical Center of Chinese PLA General Hospital, Beijing 100010, China
| | - Robert L. Macdonald
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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6
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Melnikov F, Anger LT, Hasselgren C. Toward Quantitative Models in Safety Assessment: A Case Study to Show Impact of Dose-Response Inference on hERG Inhibition Models. Int J Mol Sci 2022; 24:ijms24010635. [PMID: 36614078 PMCID: PMC9820331 DOI: 10.3390/ijms24010635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/23/2022] [Accepted: 12/24/2022] [Indexed: 12/31/2022] Open
Abstract
Due to challenges with historical data and the diversity of assay formats, in silico models for safety-related endpoints are often based on discretized data instead of the data on a natural continuous scale. Models for discretized endpoints have limitations in usage and interpretation that can impact compound design. Here, we present a consistent data inference approach, exemplified on two data sets of Ether-à-go-go-Related Gene (hERG) K+ inhibition data, for dose-response and screening experiments that are generally applicable for in vitro assays. hERG inhibition has been associated with severe cardiac effects and is one of the more prominent safety targets assessed in drug development, using a wide array of in vitro and in silico screening methods. In this study, the IC50 for hERG inhibition is estimated from diverse historical proprietary data. The IC50 derived from a two-point proprietary screening data set demonstrated high correlation (R = 0.98, MAE = 0.08) with IC50s derived from six-point dose-response curves. Similar IC50 estimation accuracy was obtained on a public thallium flux assay data set (R = 0.90, MAE = 0.2). The IC50 data were used to develop a robust quantitative model. The model's MAE (0.47) and R2 (0.46) were on par with literature statistics and approached assay reproducibility. Using a continuous model has high value for pharmaceutical projects, as it enables rank ordering of compounds and evaluation of compounds against project-specific inhibition thresholds. This data inference approach can be widely applicable to assays with quantitative readouts and has the potential to impact experimental design and improve model performance, interpretation, and acceptance across many standard safety endpoints.
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7
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Sterin I, Santos AC, Park S. Neuronal Activity Reporters as Drug Screening Platforms. MICROMACHINES 2022; 13:1500. [PMID: 36144123 PMCID: PMC9504476 DOI: 10.3390/mi13091500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 08/25/2022] [Accepted: 09/06/2022] [Indexed: 06/16/2023]
Abstract
Understanding how neuronal activity changes and detecting such changes in both normal and disease conditions is of fundamental importance to the field of neuroscience. Neuronal activity plays important roles in the formation and function of both synapses and circuits, and dysregulation of these processes has been linked to a number of debilitating diseases such as autism, schizophrenia, and epilepsy. Despite advances in our understanding of synapse biology and in how it is altered in disease, the development of therapeutics for these diseases has not advanced apace. Many neuronal activity assays have been developed over the years using a variety of platforms and approaches, but major limitations persist. Current assays, such as fluorescence indicators are not designed to monitor neuronal activity over a long time, they are typically low-throughput or lack sensitivity. These are major barriers to the development of new therapies, as drug screening needs to be both high-throughput to screen through libraries of compounds, and longitudinal to detect any effects that may emerge after continued application of the drug. This review will cover existing assays for measuring neuronal activity and highlight a live-cell assay recently developed. This assay can be performed with easily accessible lab equipment, is both scalable and longitudinal, and can be combined with most other established methods.
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Affiliation(s)
- Igal Sterin
- Department of Neurobiology, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Ana C. Santos
- Department of Neurobiology, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
- Center for Neuroscience, University of California, Davis, Davis, CA 95618, USA
| | - Sungjin Park
- Department of Neurobiology, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
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8
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Translating the measurement of hERG kinetics and drug block for CiPA to a high throughput platform. J Pharmacol Toxicol Methods 2022; 117:107192. [PMID: 35750310 DOI: 10.1016/j.vascn.2022.107192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 06/13/2022] [Accepted: 06/16/2022] [Indexed: 11/23/2022]
Abstract
The Comprehensive in vitro Proarrhythmic Assay (CiPA) has promoted use of in silico models of drug effects on cardiac repolarization to improve proarrhythmic risk prediction. These models contain a pharmacodynamic component describing drug binding to hERG channels that required in vitro data for kinetics of block, in addition to potency, to constrain them. To date, development and validation has been undertaken using data from manual patch-clamp. The application of this approach at scale requires the development of a high-throughput, automated patch-clamp (APC) implementation. Here, we present a comprehensive analysis of the implementation of the Milnes, or CiPA dynamic protocol, on an APC platform, including quality control and data analysis. Kinetics and potency of block were assessed for bepridil, cisapride, terfenadine and verapamil with data retention/QC pass rate of 21.8% overall, or as high as 50.4% when only appropriate sweep lengths were considered for drugs with faster kinetics. The variability in IC50 and kinetics between manual and APC was comparable to that seen between sites/platforms in previous APC studies of potency. Whilst the experimental success is less than observed in screens of potency alone, it is still significantly greater than manual patch. With the modifications to protocol design, including sweep length, number of repetitions, and leak correction recommended in this study, this protocol can be applied on APC to acquire data comparable to manual patch clamp.
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9
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Virginio C, Aldegheri L, Nola S, Brodbeck D, Brault L, Raveglia LF, Barilli A, Sabat M, Myers R. Identification of positive modulators of TRPM5 channel from a high-throughput screen using a fluorescent membrane potential assay. SLAS DISCOVERY : ADVANCING LIFE SCIENCES R & D 2022; 27:55-64. [PMID: 35058176 DOI: 10.1016/j.slasd.2021.10.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Transient Receptor Potential Melastatin 5 (TRPM5) is an intracellular calcium-activated cation-selective ion channel expressed in a variety of cell types. Dysfunction of this channel has recently been implied in a range of disease states including diabetes, enteric infections, inflammatory responses, parasitic infection and other pathologies. However, to date, agonists and positive modulators of this channel with sufficient selectivity to enable target validation studies have not been described, limiting the evaluation of TRPM5 biology and its potential as a drug target. We developed a high-throughput assay using a fluorescent membrane potential dye and a medium- and high-throughput electrophysiology assay using QPatch HTX and SyncroPatch 384PE. By employing these assays, we conducted a primary screening campaign and identified hit compounds as TRPM5 channel positive modulators. An initial selectivity profile confirmed hit selectivity to TRPM5 and is presented here. These small molecule TRPM5 compounds have a high potential both as early tool compounds to enable pharmacological studies of TRPM5 and as starting points for the development of potent, selective TRPM5 openers or positive modulators as novel drugs targeting several pathological states.
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Affiliation(s)
- Caterina Virginio
- Aptuit, an Evotec Company, Via Alessandro Fleming, 4, 37135 Verona, Italy.
| | - Laura Aldegheri
- Aptuit, an Evotec Company, Via Alessandro Fleming, 4, 37135 Verona, Italy
| | - Selena Nola
- Aptuit, an Evotec Company, Via Alessandro Fleming, 4, 37135 Verona, Italy
| | - Daniela Brodbeck
- Aptuit, an Evotec Company, Via Alessandro Fleming, 4, 37135 Verona, Italy
| | - Laurent Brault
- Aptuit, an Evotec Company, Via Alessandro Fleming, 4, 37135 Verona, Italy
| | - Luca F Raveglia
- Aptuit, an Evotec Company, Via Alessandro Fleming, 4, 37135 Verona, Italy
| | - Alessio Barilli
- Aptuit, an Evotec Company, Via Alessandro Fleming, 4, 37135 Verona, Italy
| | - Mark Sabat
- Takeda Pharmaceuticals, 9625 Towne Centre Drive, San Diego, CA 92121, United States
| | - Richard Myers
- Takeda Pharmaceuticals, 9625 Towne Centre Drive, San Diego, CA 92121, United States
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Abstract
Neuroelectrophysiology is an old science, dating to the 18th century when electrical activity in nerves was discovered. Such discoveries have led to a variety of neurophysiological techniques, ranging from basic neuroscience to clinical applications. These clinical applications allow assessment of complex neurological functions such as (but not limited to) sensory perception (vision, hearing, somatosensory function), and muscle function. The ability to use similar techniques in both humans and animal models increases the ability to perform mechanistic research to investigate neurological problems. Good animal to human homology of many neurophysiological systems facilitates interpretation of data to provide cause-effect linkages to epidemiological findings. Mechanistic cellular research to screen for toxicity often includes gaps between cellular and whole animal/person neurophysiological changes, preventing understanding of the complete function of the nervous system. Building Adverse Outcome Pathways (AOPs) will allow us to begin to identify brain regions, timelines, neurotransmitters, etc. that may be Key Events (KE) in the Adverse Outcomes (AO). This requires an integrated strategy, from in vitro to in vivo (and hypothesis generation, testing, revision). Scientists need to determine intermediate levels of nervous system organization that are related to an AO and work both upstream and downstream using mechanistic approaches. Possibly more than any other organ, the brain will require networks of pathways/AOPs to allow sufficient predictive accuracy. Advancements in neurobiological techniques should be incorporated into these AOP-base neurotoxicological assessments, including interactions between many regions of the brain simultaneously. Coupled with advancements in optogenetic manipulation, complex functions of the nervous system (such as acquisition, attention, sensory perception, etc.) can be examined in real time. The integration of neurophysiological changes with changes in gene/protein expression can begin to provide the mechanistic underpinnings for biological changes. Establishment of linkages between changes in cellular physiology and those at the level of the AO will allow construction of biological pathways (AOPs) and allow development of higher throughput assays to test for changes to critical physiological circuits. To allow mechanistic/predictive toxicology of the nervous system to be protective of human populations, neuroelectrophysiology has a critical role in our future.
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Affiliation(s)
- David W Herr
- Neurological and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, CPHEA/ORD, U.S. Environmental Protection Agency, Washington, NC, United States
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11
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Obergrussberger A, Rinke-Weiß I, Goetze TA, Rapedius M, Brinkwirth N, Becker N, Rotordam MG, Hutchison L, Madau P, Pau D, Dalrymple D, Braun N, Friis S, Pless SA, Fertig N. The suitability of high throughput automated patch clamp for physiological applications. J Physiol 2021; 600:277-297. [PMID: 34555195 DOI: 10.1113/jp282107] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 09/16/2021] [Indexed: 01/18/2023] Open
Abstract
Although automated patch clamp (APC) devices have been around for many years and have become an integral part of many aspects of drug discovery, high throughput instruments with gigaohm seal data quality are relatively new. Experiments where a large number of compounds are screened against ion channels are ideally suited to high throughput APC, particularly when the amount of compound available is low. Here we evaluate different APC approaches using a variety of ion channels and screening settings. We have performed a screen of 1920 compounds on GluN1/GluN2A NMDA receptors for negative allosteric modulation using both the SyncroPatch 384 and FLIPR. Additionally, we tested the effect of 36 arthropod venoms on NaV 1.9 using a single 384-well plate on the SyncroPatch 384. As an example for mutant screening, a range of acid-sensing ion channel variants were tested and the success rate increased through fluorescence-activated cell sorting (FACS) prior to APC experiments. Gigaohm seal data quality makes the 384-format accessible to recording of primary and stem cell-derived cells on the SyncroPatch 384. We show recordings in voltage and current clamp modes of stem cell-derived cardiomyocytes. In addition, the option of intracellular solution exchange enabled investigations into the effects of intracellular Ca2+ and cAMP on TRPC5 and HCN2 currents, respectively. Together, these data highlight the broad applicability and versatility of APC platforms and also outlines some limitations of the approach. KEY POINTS: High throughput automated patch clamp (APC) can be used for a variety of applications involving ion channels. Lower false positive rates were achieved using automated patch clamp versus a fluorometric imaging plate reader (FLIPR) in a high throughput compound screen against NMDA receptors. Genetic variants and mutations can be screened on a single 384-well plate to reduce variability of experimental parameters. Intracellular solution can be perfused to investigate effects of ions and second messenger systems without the need for excised patches. Primary cells and stem cell-derived cells can be used on high throughput APC with reasonable success rates for cell capture, voltage clamp measurements and action potential recordings in current clamp mode.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Nina Braun
- Department of Drug Design and Pharmacology, University of Copenhagen, Denmark
| | | | - Stephan A Pless
- Department of Drug Design and Pharmacology, University of Copenhagen, Denmark
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12
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Bell DC, Fermini B. Use of automated patch clamp in cardiac safety assessment: Past, present & future perspectives. J Pharmacol Toxicol Methods 2021; 111:107114. [PMID: 34400309 DOI: 10.1016/j.vascn.2021.107114] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
There is no doubt that automated patch clamp (APC) technology has revolutionized research in biomedical science. High throughput ion channel screening is now an integral part of the development and safety profiling of the majority of new chemical entities currently developed to address unmet medical needs. The increased throughput it provides has significantly improved the ability to overcome the time-consuming, low throughput bottlenecks resulting from the more conventional manual patch clamp method, considered the 'gold standard', for studying ion channel function and pharmacology. While systems offering the luxury of automation have only been commercially available for two decades, the road leading to this new technology is long and rich in seminal, hands-on, studies dating back as far as the 18th century. So where does this technology currently stand, and what will it look like in the future? In the current article, we review the scientific history leading to the development of APC systems, examine key drivers in the rapid development of this technology (such as failed ion channel programmes and the issue of drug-induced hERG inhibition and QT interval prolongation), highlight key capabilities and finally provide some perspective on the current and future impact of the technology on cardiac safety assessment and biomedical science.
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Affiliation(s)
- Damian C Bell
- Sophion Bioscience A/S, Ballerup, Copenhagen, Denmark.
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13
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Nakashima K, Nakao K, Matsui H. Discovery of Novel HCN4 Blockers with Unique Blocking Kinetics and Binding Properties. SLAS DISCOVERY 2021; 26:896-908. [PMID: 34041946 PMCID: PMC8293762 DOI: 10.1177/24725552211013824] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The hyperpolarization-activated cyclic nucleotide-gated 4 (HCN4) channel underlies the pacemaker currents, called “If,” in sinoatrial nodes (SANs), which regulate heart rhythm. Some HCN4 blockers such as ivabradine have been extensively studied for treating various heart diseases. Studies have shown that these blockers have diverse state dependencies and binding sites, suggesting the existence of potential chemical and functional diversity among HCN4 blockers. Here we report approaches for the identification of novel HCN4 blockers through a random screening campaign among 16,000 small-molecule compounds using an automated patch-clamp system. These molecules exhibited various blockade profiles, and their blocking kinetics and associating amino acids were determined by electrophysiological studies and site-directed mutagenesis analysis, respectively. The profiles of these blockers were distinct from those of the previously reported HCN channel blockers ivabradine and ZD7288. Notably, the mutagenesis analysis showed that blockers with potencies that were increased when the channel was open involved a C478 residue, located at the pore cavity region near the cellular surface of the plasma membrane, while those with potencies that were decreased when the channel was open involved residues Y506 and I510, located at the intracellular region of the pore gate. Thus, this study reported for the first time the discovery of novel HCN4 blockers by screening, and their profiling analysis using an automated patch-clamp system provided chemical tools that will be useful to obtain unique molecular insights into the drug-binding modes of HCN4 and may contribute to the expansion of therapeutic options in the future.
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Affiliation(s)
- Kosuke Nakashima
- Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
| | - Kenji Nakao
- Biomolecular Research Laboratories, Research, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan.,Seedsupply Inc., Fujisawa, Kanagawa, Japan
| | - Hideki Matsui
- Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
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14
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Abstract
Membrane potential (Vmem) is a fundamental biophysical signal present in all cells. Vmem signals range in time from milliseconds to days, and they span lengths from microns to centimeters. Vmem affects many cellular processes, ranging from neurotransmitter release to cell cycle control to tissue patterning. However, existing tools are not suitable for Vmem quantification in many of these areas. In this review, we outline the diverse biology of Vmem, drafting a wish list of features for a Vmem sensing platform. We then use these guidelines to discuss electrode-based and optical platforms for interrogating Vmem. On the one hand, electrode-based strategies exhibit excellent quantification but are most effective in short-term, cellular recordings. On the other hand, optical strategies provide easier access to diverse samples but generally only detect relative changes in Vmem. By combining the respective strengths of these technologies, recent advances in optical quantification of absolute Vmem enable new inquiries into Vmem biology.
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Affiliation(s)
- Julia R Lazzari-Dean
- Department of Chemistry, University of California, Berkeley, California 94720, USA; ,
| | - Anneliese M M Gest
- Department of Chemistry, University of California, Berkeley, California 94720, USA; ,
| | - Evan W Miller
- Department of Chemistry, University of California, Berkeley, California 94720, USA; ,
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, California 94720, USA
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15
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Bell DC, Fermini B. Use of automated patch clamp in cardiac safety assessment: past, present and future perspectives. J Pharmacol Toxicol Methods 2021; 110:107072. [PMID: 33962018 DOI: 10.1016/j.vascn.2021.107072] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/23/2021] [Accepted: 05/02/2021] [Indexed: 12/14/2022]
Abstract
There is no doubt that automated patch clamp (APC) technology has revolutionized research in biomedical science. High throughput ion channel screening is now an integral part of the development and safety profiling of the majority of new chemical entities currently developed to address unmet medical needs. The increased throughput it provides has significantly improved the ability to overcome the time-consuming, low throughput bottlenecks resulting from the more conventional manual patch clamp method, considered the 'gold standard', for studying ion channel function and pharmacology. While systems offering the luxury of automation have only been commercially available for two decades, the road leading to this new technology is long and rich in seminal, hands-on, studies dating back as far as the 18th century. So where does this technology currently stand, and what will it look like in the future? In the current article, we review the scientific history leading to the development of APC systems, examine key drivers in the rapid development of this technology (such as failed ion channel programmes and the issue of drug-induced hERG inhibition and QT interval prolongation), highlight key capabilities and finally provide some perspective on the current and future impact of the technology on cardiac safety assessment and biomedical science.
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16
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Bell DC, Dallas ML. Advancing Ion Channel Research with Automated Patch Clamp (APC) Electrophysiology Platforms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1349:21-32. [DOI: 10.1007/978-981-16-4254-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Obergrussberger A, Friis S, Brüggemann A, Fertig N. Automated patch clamp in drug discovery: major breakthroughs and innovation in the last decade. Expert Opin Drug Discov 2020; 16:1-5. [PMID: 32646308 DOI: 10.1080/17460441.2020.1791079] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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18
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Toh MF, Brooks JM, Strassmaier T, Haedo RJ, Puryear CB, Roth BL, Ouk K, Pin SS. Application of High-Throughput Automated Patch-Clamp Electrophysiology to Study Voltage-Gated Ion Channel Function in Primary Cortical Cultures. SLAS DISCOVERY 2020; 25:447-457. [PMID: 32003306 DOI: 10.1177/2472555220902388] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Conventionally, manual patch-clamp electrophysiological approaches are the gold standard for studying ion channel function in neurons. However, these approaches are labor-intensive, yielding low-throughput results, and are therefore not amenable for compound profiling efforts during the early stages of drug discovery. The SyncroPatch 384PE has been successfully implemented for pharmacological experiments in heterologous overexpression systems that may not reproduce the function of voltage-gated ion channels in a native, heterogeneous environment. Here, we describe a protocol allowing the characterization of endogenous voltage-gated potassium (Kv) and sodium (Nav) channel function in developing primary rat cortical cultures, allowing investigations at a significantly improved throughput compared with manual approaches. Key neuronal marker expression and microelectrode array recordings of electrophysiological activity over time correlated well with neuronal maturation. Gene expression data revealed high molecular diversity in Kv and Nav subunit composition throughout development. Voltage-clamp experiments elicited three major current components composed of inward and outward conductances. Further pharmacological experiments confirmed the endogenous expression of functional Kv and Nav channels in primary cortical neurons. The major advantages of this approach compared with conventional manual patch-clamp systems include unprecedented improvements in experimental ease and throughput for ion channel research in primary neurons. These efforts demonstrated feasibility for primary neuronal ion channel investigation with the SyncroPatch, providing the foundation for future studies characterizing biophysical changes in endogenous ion channels in primary systems associated with disease or development.
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19
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Liu C, Li T, Chen J. Role of High‐Throughput Electrophysiology in Drug Discovery. ACTA ACUST UNITED AC 2019; 87:e69. [DOI: 10.1002/cpph.69] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Chang Liu
- Department of Biochemical and Cellular PharmacologyGenentech Early Research and Development, Genentech South San Francisco California
| | - Tianbo Li
- Department of Biochemical and Cellular PharmacologyGenentech Early Research and Development, Genentech South San Francisco California
| | - Jun Chen
- Department of Biochemical and Cellular PharmacologyGenentech Early Research and Development, Genentech South San Francisco California
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20
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Bot CT, Juhasz K, Haeusermann F, Polonchuk L, Traebert M, Stoelzle-Feix S. Cross - site comparison of excitation-contraction coupling using impedance and field potential recordings in hiPSC cardiomyocytes. J Pharmacol Toxicol Methods 2018; 93:46-58. [PMID: 29940218 PMCID: PMC6146285 DOI: 10.1016/j.vascn.2018.06.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 06/18/2018] [Accepted: 06/19/2018] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Since 2005 the S7B and E14 guidances from ICH and FDA have been in place to assess a potential drug candidate's ability to cause long QT syndrome. To refine these guidelines, the FDA proposed the Comprehensive in vitro Proarrhythmia Assay (CiPA) initiative, where the assessment of drug effects on cardiac repolarization was one subject of investigation. Within the myocyte validation study, effects of pharmaceutical compounds on human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were assessed and this article will focus on the evaluation of the proarrhythmic potential of 23 blinded drugs in four hiPSC-CM cell lines. METHODS Experiments were performed on the CardioExcyte 96 at different sites. A combined readout of contractility (via impedance) and electrophysiology endpoints (field potentials) was performed. RESULTS Our data demonstrates that hERG blockers such as dofetilide and further high risk categorized compounds prolong the field potential duration. Arrhythmia were detected in both impedance as well as field potential recordings. Intermediate risk compounds induced arrhythmia in almost all cases at the highest dose. In the case of low risk compounds, either a decrease in FPDmax was observed, or not a significant change from pre-addition control values. DISCUSSION With exceptions, hiPSC-CMs are sensitive and exhibit at least 10% delayed or shortened repolarization from pre-addition values and arrhythmia after drug application and thus can provide predictive cardiac electrophysiology data. The baseline electrophysiological parameters vary between iPS cells from different sources, therefore positive and negative control recordings are recommended.
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Affiliation(s)
- Corina T Bot
- Nanion Technologies, Inc., 1 Naylon Place, Livingston, NJ 07039, USA
| | - Krisztina Juhasz
- Nanion Technologies GmbH, Ganghoferstrasse 70A, 80339 Munich, Germany; Institute for Nanoelectronics, Technische Universität München, Munich, Germany
| | - Fabian Haeusermann
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Bldg. 73/R. 103b, Grenzacherstr. 124, CH-4070 Basel, Switzerland
| | - Liudmila Polonchuk
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Bldg. 73/R. 103b, Grenzacherstr. 124, CH-4070 Basel, Switzerland
| | - Martin Traebert
- Safety Pharmacology, Novartis Pharma AG, CH-4002 Basel, Switzerland
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21
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Verstraelen P, Van Dyck M, Verschuuren M, Kashikar ND, Nuydens R, Timmermans JP, De Vos WH. Image-Based Profiling of Synaptic Connectivity in Primary Neuronal Cell Culture. Front Neurosci 2018; 12:389. [PMID: 29997468 PMCID: PMC6028601 DOI: 10.3389/fnins.2018.00389] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 05/22/2018] [Indexed: 12/04/2022] Open
Abstract
Neurological disorders display a broad spectrum of clinical manifestations. Yet, at the cellular level, virtually all these diseases converge into a common phenotype of dysregulated synaptic connectivity. In dementia, synapse dysfunction precedes neurodegeneration and cognitive impairment by several years, making the synapse a crucial entry point for the development of diagnostic and therapeutic strategies. Whereas high-resolution imaging and biochemical fractionations yield detailed insight into the molecular composition of the synapse, standardized assays are required to quickly gauge synaptic connectivity across large populations of cells under a variety of experimental conditions. Such screening capabilities have now become widely accessible with the advent of high-throughput, high-content microscopy. In this review, we discuss how microscopy-based approaches can be used to extract quantitative information about synaptic connectivity in primary neurons with deep coverage. We elaborate on microscopic readouts that may serve as a proxy for morphofunctional connectivity and we critically analyze their merits and limitations. Finally, we allude to the potential of alternative culture paradigms and integrative approaches to enable comprehensive profiling of synaptic connectivity.
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Affiliation(s)
- Peter Verstraelen
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Michiel Van Dyck
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Marlies Verschuuren
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | | | - Rony Nuydens
- Janssen Research and Development, Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Jean-Pierre Timmermans
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Winnok H. De Vos
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
- Cell Systems and Imaging, Department of Molecular Biotechnology, Ghent University, Ghent, Belgium
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22
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Brandão KO, Tabel VA, Atsma DE, Mummery CL, Davis RP. Human pluripotent stem cell models of cardiac disease: from mechanisms to therapies. Dis Model Mech 2018; 10:1039-1059. [PMID: 28883014 PMCID: PMC5611968 DOI: 10.1242/dmm.030320] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
It is now a decade since human induced pluripotent stem cells (hiPSCs) were first described. The reprogramming of adult somatic cells to a pluripotent state has become a robust technology that has revolutionised our ability to study human diseases. Crucially, these cells capture all the genetic aspects of the patient from which they were derived. Combined with advances in generating the different cell types present in the human heart, this has opened up new avenues to study cardiac disease in humans and investigate novel therapeutic approaches to treat these pathologies. Here, we provide an overview of the current state of the field regarding the generation of cardiomyocytes from human pluripotent stem cells and methods to assess them functionally, an essential requirement when investigating disease and therapeutic outcomes. We critically evaluate whether treatments suggested by these in vitro models could be translated to clinical practice. Finally, we consider current shortcomings of these models and propose methods by which they could be further improved.
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Affiliation(s)
- Karina O Brandão
- Department of Anatomy and Embryology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
| | - Viola A Tabel
- Department of Anatomy and Embryology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
| | - Douwe E Atsma
- Department of Cardiology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
| | - Christine L Mummery
- Department of Anatomy and Embryology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
| | - Richard P Davis
- Department of Anatomy and Embryology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
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23
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Mulder P, de Korte T, Dragicevic E, Kraushaar U, Printemps R, Vlaming MLH, Braam SR, Valentin JP. Predicting cardiac safety using human induced pluripotent stem cell-derived cardiomyocytes combined with multi-electrode array (MEA) technology: A conference report. J Pharmacol Toxicol Methods 2018; 91:36-42. [PMID: 29355722 DOI: 10.1016/j.vascn.2018.01.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 12/21/2017] [Accepted: 01/10/2018] [Indexed: 12/20/2022]
Abstract
Safety pharmacology studies that evaluate drug candidates for potential cardiovascular liabilities remain a critical component of drug development. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have recently emerged as a new and promising tool for preclinical hazard identification and risk assessment of drugs. Recently, Pluriomics organized its first User Meeting entitled 'Combining Pluricyte® Cardiomyocytes & MEA for Safety Pharmacology applications', consisting of scientific sessions and live demonstrations, which provided the opportunity to discuss the application of hiPSC-CMs (Pluricyte® Cardiomyocytes) in cardiac safety assessment to support early decision making in safety pharmacology. This report summarizes the outline and outcome of this Pluriomics User Meeting, which took place on November 24-25, 2016 in Leiden (The Netherlands). To reflect the content of the communications presented at this meeting we have cited key scientific articles and reviews.
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Affiliation(s)
- Petra Mulder
- Pluriomics BV, Galileiweg 8, 2333 BD Leiden, The Netherlands
| | - Tessa de Korte
- Pluriomics BV, Galileiweg 8, 2333 BD Leiden, The Netherlands.
| | - Elena Dragicevic
- Nanion Technologies GmbH, Ganghoferstraße 70a, D-80339 Munich, Germany
| | - Udo Kraushaar
- NMI Natural and Medical Sciences Institute, Markwiesenstraße 55, 72770 Reutlingen, Germany
| | | | | | - Stefan R Braam
- Pluriomics BV, Galileiweg 8, 2333 BD Leiden, The Netherlands
| | - Jean-Pierre Valentin
- Investigative Toxicology, Non-Clinical Development, UCB-Biopharma, Chemin du Foriest, 1420 Braine l'Alleud, Belgium
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24
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Obergrussberger A, Goetze TA, Brinkwirth N, Becker N, Friis S, Rapedius M, Haarmann C, Rinke-Weiß I, Stölzle-Feix S, Brüggemann A, George M, Fertig N. An update on the advancing high-throughput screening techniques for patch clamp-based ion channel screens: implications for drug discovery. Expert Opin Drug Discov 2018; 13:269-277. [DOI: 10.1080/17460441.2018.1428555] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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25
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Annecchino LA, Schultz SR. Progress in automating patch clamp cellular physiology. Brain Neurosci Adv 2018; 2:2398212818776561. [PMID: 32166142 PMCID: PMC7058203 DOI: 10.1177/2398212818776561] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 04/19/2018] [Indexed: 12/30/2022] Open
Abstract
Patch clamp electrophysiology has transformed research in the life sciences over the last few decades. Since their inception, automatic patch clamp platforms have evolved considerably, demonstrating the capability to address both voltage- and ligand-gated channels, and showing the potential to play a pivotal role in drug discovery and biomedical research. Unfortunately, the cell suspension assays to which early systems were limited cannot recreate biologically relevant cellular environments, or capture higher order aspects of synaptic physiology and network dynamics. In vivo patch clamp electrophysiology has the potential to yield more biologically complex information and be especially useful in reverse engineering the molecular and cellular mechanisms of single-cell and network neuronal computation, while capturing important aspects of human disease mechanisms and possible therapeutic strategies. Unfortunately, it is a difficult procedure with a steep learning curve, which has restricted dissemination of the technique. Luckily, in vivo patch clamp electrophysiology seems particularly amenable to robotic automation. In this review, we document the development of automated patch clamp technology, from early systems based on multi-well plates through to automated planar-array platforms, and modern robotic platforms capable of performing two-photon targeted whole-cell electrophysiological recordings in vivo.
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Affiliation(s)
- Luca A. Annecchino
- Centre for Neurotechnology and Department of Bioengineering, Imperial College London, London, UK
| | - Simon R. Schultz
- Centre for Neurotechnology and Department of Bioengineering, Imperial College London, London, UK
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26
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Pan JQ, Baez-Nieto D, Allen A, Wang HR, Cottrell JR. Developing High-Throughput Assays to Analyze and Screen Electrophysiological Phenotypes. Methods Mol Biol 2018; 1787:235-252. [PMID: 29736723 DOI: 10.1007/978-1-4939-7847-2_18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Ion channels represent nearly a quarter of all targets that currently available medications modulate, and their dysfunction underlies increasing number of human diseases. Functional analysis of ion channels have traditionally been a bottleneck in large-scale analyses. Recent technological breakthroughs in automated planar electrophysiology have democratized the technique to enable high-throughput patch clamping at scale. In this chapter, we describe the methodology to perform a phenotypic screen on voltage-gated calcium channels across many different genetic coding variations and against small-molecule modulators. We first describe the procedures to establish inducible heterologous ion channel expression in HEK293 cells, where each cell incorporates one copy of a target protein cDNA-a step that is critical for producing stable and consistent expression of ion channels. We then describe the experimental and analytical methods for analyzing the function of ion channels using high-throughput planar electrophysiology.
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Affiliation(s)
- Jen Q Pan
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
| | - David Baez-Nieto
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Andrew Allen
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Hao-Ran Wang
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jeffrey R Cottrell
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
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27
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Ellinwood N, Dobrev D, Morotti S, Grandi E. In Silico Assessment of Efficacy and Safety of I Kur Inhibitors in Chronic Atrial Fibrillation: Role of Kinetics and State-Dependence of Drug Binding. Front Pharmacol 2017; 8:799. [PMID: 29163179 PMCID: PMC5681918 DOI: 10.3389/fphar.2017.00799] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 10/23/2017] [Indexed: 12/14/2022] Open
Abstract
Current pharmacological therapy against atrial fibrillation (AF), the most common cardiac arrhythmia, is limited by moderate efficacy and adverse side effects including ventricular proarrhythmia and organ toxicity. One way to circumvent the former is to target ion channels that are predominantly expressed in atria vs. ventricles, such as KV1.5, carrying the ultra-rapid delayed-rectifier K+ current (IKur). Recently, we used an in silico strategy to define optimal KV1.5-targeting drug characteristics, including kinetics and state-dependent binding, that maximize AF-selectivity in human atrial cardiomyocytes in normal sinus rhythm (nSR). However, because of evidence for IKur being strongly diminished in long-standing persistent (chronic) AF (cAF), the therapeutic potential of drugs targeting IKur may be limited in cAF patients. Here, we sought to simulate the efficacy (and safety) of IKur inhibitors in cAF conditions. To this end, we utilized sensitivity analysis of our human atrial cardiomyocyte model to assess the importance of IKur for atrial cardiomyocyte electrophysiological properties, simulated hundreds of theoretical drugs to reveal those exhibiting anti-AF selectivity, and compared the results obtained in cAF with those in nSR. We found that despite being downregulated, IKur contributes more prominently to action potential (AP) and effective refractory period (ERP) duration in cAF vs. nSR, with ideal drugs improving atrial electrophysiology (e.g., ERP prolongation) more in cAF than in nSR. Notably, the trajectory of the AP during cAF is such that more IKur is available during the more depolarized plateau potential. Furthermore, IKur block in cAF has less cardiotoxic effects (e.g., AP duration not exceeding nSR values) and can increase Ca2+ transient amplitude thereby enhancing atrial contractility. We propose that in silico strategies such as that presented here should be combined with in vitro and in vivo assays to validate model predictions and facilitate the ongoing search for novel agents against AF.
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Affiliation(s)
- Nicholas Ellinwood
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Dobromir Dobrev
- West German Heart and Vascular Center, Institute of Pharmacology, University Duisburg-Essen, Essen, Germany
| | - Stefano Morotti
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Eleonora Grandi
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
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28
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Action potential-based MEA platform for in vitro screening of drug-induced cardiotoxicity using human iPSCs and rat neonatal myocytes. J Pharmacol Toxicol Methods 2017; 87:48-52. [DOI: 10.1016/j.vascn.2017.05.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 05/10/2017] [Accepted: 05/20/2017] [Indexed: 11/22/2022]
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29
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Neveshkin A, Citak F, Ball V, Winterhalter M. Polydopamine Coating To Stabilize a Free-Standing Lipid Bilayer for Channel Sensing. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:7256-7262. [PMID: 28657327 DOI: 10.1021/acs.langmuir.7b01959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
An appropriate method to study the function of membrane channels is to insert them into free-standing lipid bilayers and to record the ion conductance across the membrane. The insulating property of a free-standing lipid bilayer versus the single-channel conductivity provides sufficient sensitivity to detect minor changes in the pathway of ions along the channel. A potential application is to use membrane channels as label-free sensors for molecules, with DNA sequencing as its most prominent application. However, the inherent instability of free-standing bilayers limits broader use as a biosensor. Here we report on a possible stabilization of free-standing lipid bilayers using polydopamine deposition from dopamine-containing solutions in the presence of an oxidant. This stabilization treatment can be initiated after protein reconstitution and is compatible with most reconstitution protocols.
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Affiliation(s)
- Alexander Neveshkin
- Jacobs University Bremen , Campus Ring 1, D-28759 Bremen, Germany
- Yuri Gagarin State Technical University of Saratov , 77 Politechnicheskaya Street, Saratov, Russia , 410054
| | - Funda Citak
- Jacobs University Bremen , Campus Ring 1, D-28759 Bremen, Germany
| | - Vincent Ball
- Institut National de la Santé et de la Recherche Médicale , Unité Mixte de Recherche 1121, 11 Rue Humann, 67085 Strasbourg Cedex, France
- Université de Strasbourg, Faculté de Chirurgie Dentaire , 8 Rue Sainte Elisabeth, 67000 Strasbourg, France
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30
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Bell DC, Dallas ML. Using automated patch clamp electrophysiology platforms in pain-related ion channel research: insights from industry and academia. Br J Pharmacol 2017. [PMID: 28622411 DOI: 10.1111/bph.13916] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Automated patch clamp (APC) technology was first developed at the turn of the millennium. The increased throughput it afforded promised a new paradigm in ion channel recordings, offering the potential to overcome the time-consuming, low-throughput bottleneck, arising from manual patch clamp investigations. This has relevance to the fast-paced development of novel therapies for chronic pain. This review highlights the advances in technology, using select examples that have facilitated APC usage in both industry and academia. It covers both first generation and the latest developments in second-generation platforms. In addition, it also provides an overview of the pain research field and how APC platforms have furthered our understanding of ion channel research and the development of pharmacological tools and therapeutics. APC platforms have much to offer to the ion channel research community, and this review highlights areas of best practice for both academia and industry. The impact of APC platforms and the prospects of ion channel research and improved therapeutics for chronic pain will be evaluated. LINKED ARTICLES This article is part of a themed section on Recent Advances in Targeting Ion Channels to Treat Chronic Pain. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.12/issuetoc.
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Affiliation(s)
| | - Mark L Dallas
- School of Pharmacy, University of Reading, Reading, UK
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Molokanova E, Mercola M, Savchenko A. Bringing new dimensions to drug discovery screening: impact of cellular stimulation technologies. Drug Discov Today 2017; 22:1045-1055. [PMID: 28179145 DOI: 10.1016/j.drudis.2017.01.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 12/09/2016] [Accepted: 01/27/2017] [Indexed: 01/08/2023]
Abstract
The current mandate for the drug discovery industry is to develop more efficient drugs faster while reducing the costs associated with their development. Incorporation of cell stimulation technologies during screening assays is expected to revolutionize the discovery of novel drugs as well as safety pharmacology. In this review, we highlight 'classical' and emerging cell stimulation technologies that provide the ability to evaluate the effects of drug candidates on cells in different functional states to assess clinically relevant phenotypes.
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Affiliation(s)
- Elena Molokanova
- Nanotools Bioscience, Encinitas, CA 92024, USA; Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Mark Mercola
- Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA; Department of Medicine and Cardiovascular Institute, Stanford University, Palo Alto, CA 94304, USA
| | - Alex Savchenko
- Department of Medicine and Cardiovascular Institute, Stanford University, Palo Alto, CA 94304, USA; Department of Pediatrics, University of California-San Diego, La Jolla, CA 92093, USA.
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32
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Chow EKH. The 2017 SLAS Technology Ten: Translating Life Sciences Innovation. SLAS Technol 2017; 22:3-6. [DOI: 10.1177/2472630316683633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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33
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Lynch JW, Zhang Y, Talwar S, Estrada-Mondragon A. Glycine Receptor Drug Discovery. ADVANCES IN PHARMACOLOGY 2017; 79:225-253. [DOI: 10.1016/bs.apha.2017.01.003] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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