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Xia S, Bozóky Z, Di Paola M, Laselva O, Ahmadi S, Jiang JX, Pitstick AL, Jiang C, Rotin D, Mayhew CN, Jones NL, Bear CE. High-Throughput Functional Analysis of CFTR and Other Apically Localized Proteins in iPSC-Derived Human Intestinal Organoids. Cells 2021; 10:cells10123419. [PMID: 34943927 PMCID: PMC8699884 DOI: 10.3390/cells10123419] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/26/2021] [Accepted: 11/30/2021] [Indexed: 01/15/2023] Open
Abstract
Induced Pluripotent Stem Cells (iPSCs) can be differentiated into epithelial organoids that recapitulate the relevant context for CFTR and enable testing of therapies targeting Cystic Fibrosis (CF)-causing mutant proteins. However, to date, CF-iPSC-derived organoids have only been used to study pharmacological modulation of mutant CFTR channel activity and not the activity of other disease-relevant membrane protein constituents. In the current work, we describe a high-throughput, fluorescence-based assay of CFTR channel activity in iPSC-derived intestinal organoids and describe how this method can be adapted to study other apical membrane proteins. Specifically, we show how this assay can be employed to study CFTR and ENaC channels and an electrogenic acid transporter in the same iPSC-derived intestinal tissue. This phenotypic platform promises to expand CF therapy discovery to include strategies that target multiple determinants of epithelial fluid transport.
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Affiliation(s)
- Sunny Xia
- Molecular Medicine, Hospital for Sick Children, 686 Bay St, Toronto, ON M5G 0A4, Canada; (S.X.); (Z.B.); (O.L.); (J.X.J.)
- Cell Biology, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada; (C.J.); (D.R.); (N.L.J.)
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada;
| | - Zoltán Bozóky
- Molecular Medicine, Hospital for Sick Children, 686 Bay St, Toronto, ON M5G 0A4, Canada; (S.X.); (Z.B.); (O.L.); (J.X.J.)
| | - Michelle Di Paola
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada;
| | - Onofrio Laselva
- Molecular Medicine, Hospital for Sick Children, 686 Bay St, Toronto, ON M5G 0A4, Canada; (S.X.); (Z.B.); (O.L.); (J.X.J.)
- Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
| | - Saumel Ahmadi
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63110, USA;
| | - Jia Xin Jiang
- Molecular Medicine, Hospital for Sick Children, 686 Bay St, Toronto, ON M5G 0A4, Canada; (S.X.); (Z.B.); (O.L.); (J.X.J.)
| | - Amy L. Pitstick
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA; (A.L.P.); (C.N.M.)
| | - Chong Jiang
- Cell Biology, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada; (C.J.); (D.R.); (N.L.J.)
| | - Daniela Rotin
- Cell Biology, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada; (C.J.); (D.R.); (N.L.J.)
- Department of Biochemistry, University of Toronto, Toronto, ON M5G 0A4, Canada
| | - Christopher N. Mayhew
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA; (A.L.P.); (C.N.M.)
| | - Nicola L. Jones
- Cell Biology, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada; (C.J.); (D.R.); (N.L.J.)
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada;
- Department of Paediatrics, University of Toronto, Toronto, ON M5G 0A4, Canada
| | - Christine E. Bear
- Molecular Medicine, Hospital for Sick Children, 686 Bay St, Toronto, ON M5G 0A4, Canada; (S.X.); (Z.B.); (O.L.); (J.X.J.)
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada;
- Department of Biochemistry, University of Toronto, Toronto, ON M5G 0A4, Canada
- Correspondence:
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Zyrianova T, Lopez B, Liao A, Gu C, Wong L, Ottolia M, Olcese R, Schwingshackl A. BK Channels Regulate LPS-induced CCL-2 Release from Human Pulmonary Endothelial Cells. Am J Respir Cell Mol Biol 2021; 64:224-234. [PMID: 33217242 PMCID: PMC7874395 DOI: 10.1165/rcmb.2020-0228oc] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 11/05/2020] [Indexed: 11/24/2022] Open
Abstract
We recently established a role for the stretch-activated two-pore-domain K+ (K2P) channel TREK-1 (K2P2.1) in inflammatory cytokine secretion using models of hyperoxia-, mechanical stretch-, and TNF-α-induced acute lung injury. We have now discovered the expression of large conductance, Ca2+-activated K+ (BK) channels in human pulmonary microvascular endothelial cells and primary human alveolar epithelial cells using semiquantitative real-time PCR, IP and Western blot, and investigated their role in inflammatory cytokine secretion using an LPS-induced acute lung injury model. As expected, LPS induced IL-6 and CCL-2 secretion from pulmonary endothelial and epithelial cells. BK activation with NS1619 decreased LPS-induced CCL-2 but not IL-6 secretion from endothelial cells and had no effect on epithelial cells, although fluorometric assays revealed that BK activation hyperpolarized the plasma membrane potential (Em) of both cell types. Interestingly, BK inhibition (Paxilline) did not alter cytokine secretion or the Em in either cell type. Furthermore, LPS treatment by itself did not affect the Em or intracellular Ca2+ concentrations. Therefore, we propose BK channel activation as a novel targeted approach to counteract LPS-induced CCL-2 secretion from endothelial cells. This protective effect appears to occur via Em hyperpolarization but independent of intracellular Ca2+ concentrations.
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Affiliation(s)
| | | | | | | | | | - Michela Ottolia
- Department of Anesthesiology and Perioperative Medicine, and
| | - Riccardo Olcese
- Department of Anesthesiology and Perioperative Medicine, and
- Department of Physiology, University of California Los Angeles, Los Angeles, California
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Amaral MD. How to determine the mechanism of action of CFTR modulator compounds: A gateway to theranostics. Eur J Med Chem 2020; 210:112989. [PMID: 33190956 DOI: 10.1016/j.ejmech.2020.112989] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/02/2020] [Accepted: 11/02/2020] [Indexed: 12/12/2022]
Abstract
The greatest challenge of 21st century biology is to fully understand mechanisms of disease to drive new approaches and medical innovation. Parallel to this is the huge biomedical endeavour of treating people through personalized medicine. Until now all CFTR modulator drugs that have entered clinical trials have been genotype-dependent. An emerging alternative is personalized/precision medicine in CF, i.e., to determine whether rare CFTR mutations respond to existing (or novel) CFTR modulator drugs by pre-assessing them directly on patient's tissues ex vivo, an approach also now termed theranostics. To administer the right drug to the right person it is essential to understand how drugs work, i.e., to know their mechanism of action (MoA), so as to predict their applicability, not just in certain mutations but also possibly in other diseases that share the same defect/defective pathway. Moreover, an understanding the MoA of a drug before it is tested in clinical trials is the logical path to drug discovery and can increase its chance for success and hence also approval. In conclusion, the most powerful approach to determine the MoA of a compound is to understand the underlying biology. Novel large datasets of intervenients in most biological processes, namely those emerging from the post-genomic era tools, are available and should be used to help in this task.
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Affiliation(s)
- Margarida D Amaral
- BioISI - Biosystems & Integrative Sciences Institute, Lisboa, Faculty of Sciences, University of Lisboa, Portugal.
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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.
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Affiliation(s)
- Michael J Booth
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK.
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Atkin TA, Maher CM, Gerlach AC, Gay BC, Antonio BM, Santos SC, Padilla KM, Rader J, Krafte DS, Fox MA, Stewart GR, Petrovski S, Devinsky O, Might M, Petrou S, Goldstein DB. A comprehensive approach to identifying repurposed drugs to treat SCN8A epilepsy. Epilepsia 2018; 59:802-813. [PMID: 29574705 DOI: 10.1111/epi.14037] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/05/2018] [Indexed: 01/28/2023]
Abstract
OBJECTIVE Many previous studies of drug repurposing have relied on literature review followed by evaluation of a limited number of candidate compounds. Here, we demonstrate the feasibility of a more comprehensive approach using high-throughput screening to identify inhibitors of a gain-of-function mutation in the SCN8A gene associated with severe pediatric epilepsy. METHODS We developed cellular models expressing wild-type or an R1872Q mutation in the Nav 1.6 sodium channel encoded by SCN8A. Voltage clamp experiments in HEK-293 cells expressing the SCN8A R1872Q mutation demonstrated a leftward shift in sodium channel activation as well as delayed inactivation; both changes are consistent with a gain-of-function mutation. We next developed a fluorescence-based, sodium flux assay and used it to assess an extensive library of approved drugs, including a panel of antiepileptic drugs, for inhibitory activity in the mutated cell line. Lead candidates were evaluated in follow-on studies to generate concentration-response curves for inhibiting sodium influx. Select compounds of clinical interest were evaluated by electrophysiology to further characterize drug effects on wild-type and mutant sodium channel functions. RESULTS The screen identified 90 drugs that significantly inhibited sodium influx in the R1872Q cell line. Four drugs of potential clinical interest-amitriptyline, carvedilol, nilvadipine, and carbamazepine-were further investigated and demonstrated concentration-dependent inhibition of sodium channel currents. SIGNIFICANCE A comprehensive drug repurposing screen identified potential new candidates for the treatment of epilepsy caused by the R1872Q mutation in the SCN8A gene.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Slavé Petrovski
- Pairnomix, Plymouth, MN, USA.,Florey Institute for Neuroscience and Mental Health and Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
| | - Orrin Devinsky
- Pairnomix, Plymouth, MN, USA.,Department of Neurology, New York University Medical Center, New York, NY, USA
| | - Matthew Might
- Pairnomix, Plymouth, MN, USA.,University of Alabama at Birmingham, Birmingham, AL, USA
| | - Steven Petrou
- Pairnomix, Plymouth, MN, USA.,Florey Institute for Neuroscience and Mental Health and Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
| | - David B Goldstein
- Pairnomix, Plymouth, MN, USA.,Institute for Genomic Medicine, Columbia University Medical Center, New York, NY, USA
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Image-based cell-size estimation for baculovirus quantification. Biotechniques 2017; 63:161-168. [DOI: 10.2144/000114595] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 08/09/2017] [Indexed: 11/23/2022] Open
Abstract
Measurement of virus concentration is essential for effective virus-based transfection technologies. Here, we describe a user-friendly, image-based cell-size estimation (ICSE) assay for baculovirus quantification that relies on automated determination of cell diameters from bright-field microscopy images. In the ICSE assay, microplate-based imaging systems and our custom ICSE-Tools software enable measurement of cell morphological parameters over time. Results from the ICSE assay were in agreement with virus concentration measurements obtained using the traditional plaque assay as well as the Coulter principle–based cell-size measurement assay. ICSE-Tools is designed for data organization and image analysis from microplate-based imaging systems, and is freely available at www.gpcr.ut.ee/software.html .
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Fundamentals of Baculovirus Expression and Applications. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 896:187-97. [DOI: 10.1007/978-3-319-27216-0_12] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Du Y, Days E, Romaine I, Abney KK, Kaufmann K, Sulikowski G, Stauffer S, Lindsley CW, Weaver CD. Development and validation of a thallium flux-based functional assay for the sodium channel NaV1.7 and its utility for lead discovery and compound profiling. ACS Chem Neurosci 2015; 6:871-8. [PMID: 25879403 DOI: 10.1021/acschemneuro.5b00004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Ion channels are critical for life, and they are targets of numerous drugs. The sequencing of the human genome has revealed the existence of hundreds of different ion channel subunits capable of forming thousands of ion channels. In the face of this diversity, we only have a few selective small-molecule tools to aid in our understanding of the role specific ion channels in physiology which may in turn help illuminate their therapeutic potential. Although the advent of automated electrophysiology has increased the rate at which we can screen for and characterize ion channel modulators, the technique's high per-measurement cost and moderate throughput compared to other high-throughput screening approaches limit its utility for large-scale high-throughput screening. Therefore, lower cost, more rapid techniques are needed. While ion channel types capable of fluxing calcium are well-served by low cost, very high-throughput fluorescence-based assays, other channel types such as sodium channels remain underserved by present functional assay techniques. In order to address this shortcoming, we have developed a thallium flux-based assay for sodium channels using the NaV1.7 channel as a model target. We show that the assay is able to rapidly and cost-effectively identify NaV1.7 inhibitors thus providing a new method useful for the discovery and profiling of sodium channel modulators.
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Affiliation(s)
| | | | | | - Kris K. Abney
- Meharry Medical
College Program in Pharmacology, Nashville, Tennessee 37208, United States
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