51
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O’Shea C, Holmes AP, Winter J, Correia J, Ou X, Dong R, He S, Kirchhof P, Fabritz L, Rajpoot K, Pavlovic D. Cardiac Optogenetics and Optical Mapping - Overcoming Spectral Congestion in All-Optical Cardiac Electrophysiology. Front Physiol 2019; 10:182. [PMID: 30899227 PMCID: PMC6416196 DOI: 10.3389/fphys.2019.00182] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Accepted: 02/14/2019] [Indexed: 12/30/2022] Open
Abstract
Optogenetic control of the heart is an emergent technology that offers unparalleled spatio-temporal control of cardiac dynamics via light-sensitive ion pumps and channels (opsins). This fast-evolving technique holds broad scope in both clinical and basic research setting. Combination of optogenetics with optical mapping of voltage or calcium fluorescent probes facilitates 'all-optical' electrophysiology, allowing precise optogenetic actuation of cardiac tissue with high spatio-temporal resolution imaging of action potential and calcium transient morphology and conduction patterns. In this review, we provide a synopsis of optogenetics and discuss in detail its use and compatibility with optical interrogation of cardiac electrophysiology. We briefly discuss the benefits of all-optical cardiac control and electrophysiological interrogation compared to traditional techniques, and describe mechanisms, unique features and limitations of optically induced cardiac control. In particular, we focus on state-of-the-art setup design, challenges in light delivery and filtering, and compatibility of opsins with fluorescent reporters used in optical mapping. The interaction of cardiac tissue with light, and physical and computational approaches to overcome the 'spectral congestion' that arises from the combination of optogenetics and optical mapping are discussed. Finally, we summarize recent preclinical work applications of combined cardiac optogenetics and optical mapping approach.
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Affiliation(s)
- Christopher O’Shea
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
- School of Computer Science, University of Birmingham, Birmingham, United Kingdom
- EPSRC Centre for Doctoral Training in Physical Sciences for Health, School of Chemistry, University of Birmingham, Birmingham, United Kingdom
| | - Andrew P. Holmes
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
- Institute of Clinical Sciences, University of Birmingham, Birmingham, United Kingdom
| | - James Winter
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Joao Correia
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Xianhong Ou
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease/Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Ruirui Dong
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease/Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Shicheng He
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease/Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Paulus Kirchhof
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
- Department of Cardiology, UHB NHS Trust, Birmingham, United Kingdom
| | - Larissa Fabritz
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
- Department of Cardiology, UHB NHS Trust, Birmingham, United Kingdom
| | - Kashif Rajpoot
- School of Computer Science, University of Birmingham, Birmingham, United Kingdom
| | - Davor Pavlovic
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
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Optical Recording of Action Potentials in Human Induced Pluripotent Stem Cell-Derived Cardiac Single Cells and Monolayers Generated from Long QT Syndrome Type 1 Patients. Stem Cells Int 2019; 2019:7532657. [PMID: 30956674 PMCID: PMC6431403 DOI: 10.1155/2019/7532657] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 11/06/2018] [Indexed: 01/08/2023] Open
Abstract
Induced pluripotent stem cells (iPSCs) from type 1 long QT (LQT1) patients can differentiate into cardiomyocytes (CMs) including ventricular cells to recapitulate the disease phenotype. Although optical recordings using membrane potential dyes to monitor action potentials (APs) were reported, no study has investigated the disease phenotypes of cardiac channelopathy in association with the cardiac subtype at the single-cell level. We induced iPSC-CMs from three control and three LQT1 patients. Single-cell analysis using a fast-responding dye confirmed that ventricular cells were the dominant subtype (control-iPSC-CMs: 98%, 88%, 91%; LQT1-iPSC-CMs: 95%, 79%, 92%). In addition, LQT1-iPSC-ventricular cells displayed an increased frequency of early afterdepolarizations (pvalue = 0.031). Cardiomyocyte monolayers constituted mostly of ventricular cells derived from LQT1-iPSCs showed prolonged AP duration (APD) (pvalue = 0.000096). High-throughput assays using cardiomyocyte monolayers in 96-well plates demonstrated that IKr inhibitors prolonged APDs in both control- and LQT1-iPSC-CM monolayers. We confirmed that the optical recordings of APs in single cells and monolayers derived from control- and LQT1-iPSC-CMs can be used to assess arrhythmogenicity, supporting the feasibility of membrane potential dye-based high-throughput screening to study ventricular arrhythmias caused by genetic channelopathy or cardiotoxic drugs.
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53
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Multimodal on-axis platform for all-optical electrophysiology with near-infrared probes in human stem-cell-derived cardiomyocytes. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 154:62-70. [PMID: 30850184 DOI: 10.1016/j.pbiomolbio.2019.02.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/04/2019] [Accepted: 02/11/2019] [Indexed: 12/27/2022]
Abstract
Combined optogenetic stimulation and optical imaging permit scalable, contact-free high-throughput probing of cellular electrophysiology and optimization of stem-cell derived excitable cells, such as neurons and muscle cells. We report a new "on-axis" configuration (combined single optical path for stimulation and for multiparameter imaging) of OptoDyCE, our all-optical platform for studying human induced pluripotent stem-cell-derived cardiomyocytes (hiPSC-CMs) and other cell types, optically driven by Channelrhodopsin2 (ChR2). This solid-state system integrates optogenetic stimulation with temporally-multiplexed simultaneous recording of membrane voltage (Vm) and intracellular calcium ([Ca2+]i) dynamics using a single photodetector. We demonstrate the capacity for combining multiple spectrally-compatible actuators and sensors, including newer high-performance near-infrared (NIR) voltage probes BeRST1 and Di-4-ANBDQBS, to record complex spatiotemporal responses of hiPSC-CMs to drugs in a high-throughput manner.
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54
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A Software Architecture to Mimic a Ventricular Tachycardia in Intact Murine Hearts by Means of an All-Optical Platform. Methods Protoc 2019; 2:mps2010007. [PMID: 31164591 PMCID: PMC6481051 DOI: 10.3390/mps2010007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/29/2018] [Accepted: 01/04/2019] [Indexed: 11/17/2022] Open
Abstract
Optogenetics is an emerging method that uses light to manipulate electrical activity in excitable cells exploiting the interaction between light and light-sensitive depolarizing ion channels, such as channelrhodopsin-2 (ChR2). Initially used in the neuroscience, it has been adopted in cardiac research where the expression of ChR2 in cardiac preparations allows optical pacing, resynchronization and defibrillation. Recently, optogenetics has been leveraged to manipulate cardiac electrical activity in the intact heart in real-time. This new approach was applied to simulate a re-entrant circuit across the ventricle. In this technical note, we describe the development and the implementation of a new software package for real-time optogenetic intervention. The package consists of a single LabVIEW program that simultaneously captures images at very high frame rates and delivers precisely timed optogenetic stimuli based on the content of the images. The software implementation guarantees closed-loop optical manipulation at high temporal resolution by processing the raw data in workstation memory. We demonstrate that this strategy allows the simulation of a ventricular tachycardia with high stability and with a negligible loss of data with a temporal resolution of up to 1 ms.
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55
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Zhang H, Yu H, Walcott GP, Paskaranandavadivel N, Cheng LK, O’Grady G, Rogers JM. High-resolution optical mapping of gastric slow wave propagation. Neurogastroenterol Motil 2019; 31:e13449. [PMID: 30129082 PMCID: PMC6724537 DOI: 10.1111/nmo.13449] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/20/2018] [Accepted: 07/18/2018] [Indexed: 01/03/2023]
Abstract
BACKGROUND Improved understanding of the details of gastric slow wave propagation could potentially inform new diagnosis and treatment options for stomach motility disorders. Optical mapping has been used extensively in cardiac electrophysiology. Although optical mapping has a number of advantages relative to electrical mapping, optical signals are highly sensitive to motion artifact. We recently introduced a novel cardiac optical mapping method that corrects motion artifact and enables optical mapping to be performed in beating hearts. Here, we reengineer the method as an experimental tool to map gastric slow waves. METHODS The method was developed and tested in 12 domestic farm pigs. Stomachs were exposed by laparotomy and stained with the voltage-sensitive fluorescence dye di-4-ANEPPS through a catheter placed in the gastroepiploic artery. Fiducial markers for motion tracking were attached to the serosa. The dye was excited by 450 or 505 nm light on alternate frames of an imaging camera running at 300 Hz. Emitted fluorescence was imaged between 607 and 695 nm. The optical slow wave signal was reconstructed using a combination of motion tracking and excitation ratiometry to suppress motion artifact. Optical slow wave signals were compared with simultaneously recorded bipolar electrograms and suction electrode signals, which approximate membrane potential. KEY RESULTS The morphology of optical slow waves was consistent with previously published microelectrode recordings and simultaneously recorded suction electrode signals. The timing of the optical slow wave signals was consistent with the bipolar electrograms. CONCLUSIONS AND INFERENCES Optical mapping of slow wave propagation in the stomach is feasible.
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Affiliation(s)
- Hanyu Zhang
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Han Yu
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Gregory P. Walcott
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama, United States,Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Niranchan Paskaranandavadivel
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand,Department of Surgery, The University of Auckland, Auckland, New Zealand
| | - Leo K Cheng
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand,Department of Surgery, Vanderbilt University, Nashville, Tennessee, United States
| | - Gregory O’Grady
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand,Department of Surgery, The University of Auckland, Auckland, New Zealand
| | - Jack M. Rogers
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama, United States,Corresponding author: 1670 University Blvd, Volker Hall B140, Birmingham, AL, 35294, USA, (205) 975-2102,
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Natriuretic Peptide Receptor-C Protects Against Angiotensin II-Mediated Sinoatrial Node Disease in Mice. JACC Basic Transl Sci 2018; 3:824-843. [PMID: 30623142 PMCID: PMC6314975 DOI: 10.1016/j.jacbts.2018.08.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 08/15/2018] [Accepted: 08/16/2018] [Indexed: 12/19/2022]
Abstract
SAN disease is prevalent in hypertension and heart failure and can be induced by chronic Ang II treatment in mice. Ang II caused SAN disease in mice in association with impaired electrical conduction, reduction in the hyperpolarization-activated current (If) in SAN myocytes, and increased SAN fibrosis. Ang II-induced SAN disease was worsened in mice lacking NPR-C in association with enhanced SAN fibrosis. Mice co-treated with Ang II and an NPR-C agonist (cANF) were protected from SAN disease. NPR-C may represent a new target to protect against Ang II-induced SAN disease.
Sinoatrial node (SAN) disease mechanisms are poorly understood, and therapeutic options are limited. Natriuretic peptide(s) (NP) are cardioprotective hormones whose effects can be mediated partly by the NP receptor C (NPR-C). We investigated the role of NPR-C in angiotensin II (Ang II)-mediated SAN disease in mice. Ang II caused SAN disease due to impaired electrical activity in SAN myocytes and increased SAN fibrosis. Strikingly, Ang II treatment in NPR-C−/− mice worsened SAN disease, whereas co-treatment of wild-type mice with Ang II and a selective NPR-C agonist (cANF) prevented SAN dysfunction. NPR-C may represent a new target to protect against the development of Ang II-induced SAN disease.
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Key Words
- AP, action potential
- Ang II, angiotensin II
- CV, conduction velocity
- DD, diastolic depolarization
- Gmax, maximum conductance
- HR, heart rate
- ICa,L, L-type calcium current
- ICa,T, T-type calcium current
- INCX, sodium–calcium exchanger current
- IV, current voltage relationship
- If, hyperpolarization-activated current
- NP, natriuretic peptide
- NPR, natriuretic peptide receptor
- NPR-C, natriuretic peptide receptor C
- SAN, sinoatrial node
- SBP, systolic blood pressure
- V1/2(act), voltage for 50% channel activation
- cSNRT, corrected sinoatrial node recovery time
- fibrosis
- hypertension
- ion currents
- natriuretic peptide
- sinoatrial node
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Hansen BJ, Li N, Helfrich KM, Abudulwahed SH, Artiga E, Joseph M, Mohler PJ, Hummel JD, Fedorov VV. First In Vivo Use of High-Resolution Near-Infrared Optical Mapping to Assess Atrial Activation During Sinus Rhythm and Atrial Fibrillation in a Large Animal Model. Circ Arrhythm Electrophysiol 2018; 11:e006870. [PMID: 30562105 PMCID: PMC6300135 DOI: 10.1161/circep.118.006870] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Brian J. Hansen
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
- Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Ning Li
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
- Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Katelynn M. Helfrich
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Suhaib H. Abudulwahed
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Esthela Artiga
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Matt Joseph
- Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Peter J Mohler
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
- Department of Internal Medicine; The Ohio State University Wexner Medical Center, Columbus, OH
| | - John D. Hummel
- Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
- Department of Internal Medicine; The Ohio State University Wexner Medical Center, Columbus, OH
| | - Vadim V. Fedorov
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
- Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
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58
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Hansen BJ, Csepe TA, Zhao J, Ignozzi AJ, Hummel JD, Fedorov VV. Maintenance of Atrial Fibrillation: Are Reentrant Drivers With Spatial Stability the Key? Circ Arrhythm Electrophysiol 2018; 9:CIRCEP.116.004398. [PMID: 27729340 DOI: 10.1161/circep.116.004398] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 09/07/2016] [Indexed: 11/16/2022]
Affiliation(s)
- Brian J Hansen
- From the Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus (B.J.H., T.A.C., A.J.I., J.D.H., V.V.F.); and Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.)
| | - Thomas A Csepe
- From the Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus (B.J.H., T.A.C., A.J.I., J.D.H., V.V.F.); and Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.)
| | - Jichao Zhao
- From the Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus (B.J.H., T.A.C., A.J.I., J.D.H., V.V.F.); and Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.)
| | - Anthony J Ignozzi
- From the Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus (B.J.H., T.A.C., A.J.I., J.D.H., V.V.F.); and Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.)
| | - John D Hummel
- From the Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus (B.J.H., T.A.C., A.J.I., J.D.H., V.V.F.); and Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.)
| | - Vadim V Fedorov
- From the Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus (B.J.H., T.A.C., A.J.I., J.D.H., V.V.F.); and Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.).
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59
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Scardigli M, Müllenbroich C, Margoni E, Cannazzaro S, Crocini C, Ferrantini C, Coppini R, Yan P, Loew LM, Campione M, Bocchi L, Giulietti D, Cerbai E, Poggesi C, Bub G, Pavone FS, Sacconi L. Real-time optical manipulation of cardiac conduction in intact hearts. J Physiol 2018; 596:3841-3858. [PMID: 29989169 PMCID: PMC6117584 DOI: 10.1113/jp276283] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 07/05/2018] [Indexed: 11/28/2022] Open
Abstract
Key points Although optogenetics has clearly demonstrated the feasibility of cardiac manipulation, current optical stimulation strategies lack the capability to react acutely to ongoing cardiac wave dynamics. Here, we developed an all‐optical platform to monitor and control electrical activity in real‐time. The methodology was applied to restore normal electrical activity after atrioventricular block and to manipulate the intraventricular propagation of the electrical wavefront. The closed‐loop approach was also applied to simulate a re‐entrant circuit across the ventricle. The development of this innovative optical methodology provides the first proof‐of‐concept that a real‐time all‐optical stimulation can control cardiac rhythm in normal and abnormal conditions.
Abstract Optogenetics has provided new insights in cardiovascular research, leading to new methods for cardiac pacing, resynchronization therapy and cardioversion. Although these interventions have clearly demonstrated the feasibility of cardiac manipulation, current optical stimulation strategies do not take into account cardiac wave dynamics in real time. Here, we developed an all‐optical platform complemented by integrated, newly developed software to monitor and control electrical activity in intact mouse hearts. The system combined a wide‐field mesoscope with a digital projector for optogenetic activation. Cardiac functionality could be manipulated either in free‐run mode with submillisecond temporal resolution or in a closed‐loop fashion: a tailored hardware and software platform allowed real‐time intervention capable of reacting within 2 ms. The methodology was applied to restore normal electrical activity after atrioventricular block, by triggering the ventricle in response to optically mapped atrial activity with appropriate timing. Real‐time intraventricular manipulation of the propagating electrical wavefront was also demonstrated, opening the prospect for real‐time resynchronization therapy and cardiac defibrillation. Furthermore, the closed‐loop approach was applied to simulate a re‐entrant circuit across the ventricle demonstrating the capability of our system to manipulate heart conduction with high versatility even in arrhythmogenic conditions. The development of this innovative optical methodology provides the first proof‐of‐concept that a real‐time optically based stimulation can control cardiac rhythm in normal and abnormal conditions, promising a new approach for the investigation of the (patho)physiology of the heart. Although optogenetics has clearly demonstrated the feasibility of cardiac manipulation, current optical stimulation strategies lack the capability to react acutely to ongoing cardiac wave dynamics. Here, we developed an all‐optical platform to monitor and control electrical activity in real‐time. The methodology was applied to restore normal electrical activity after atrioventricular block and to manipulate the intraventricular propagation of the electrical wavefront. The closed‐loop approach was also applied to simulate a re‐entrant circuit across the ventricle. The development of this innovative optical methodology provides the first proof‐of‐concept that a real‐time all‐optical stimulation can control cardiac rhythm in normal and abnormal conditions.
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Affiliation(s)
- M Scardigli
- European Laboratory for Non-Linear Spectroscopy, Florence, 50019, Italy.,National Institute of Optics, National Research Council, Florence, 50125, Italy
| | - C Müllenbroich
- European Laboratory for Non-Linear Spectroscopy, Florence, 50019, Italy.,National Institute of Optics, National Research Council, Florence, 50125, Italy
| | - E Margoni
- European Laboratory for Non-Linear Spectroscopy, Florence, 50019, Italy.,Department of Physics, University of Pisa, Pisa, 56127, Italy
| | - S Cannazzaro
- European Laboratory for Non-Linear Spectroscopy, Florence, 50019, Italy.,National Institute of Optics, National Research Council, Florence, 50125, Italy
| | - C Crocini
- European Laboratory for Non-Linear Spectroscopy, Florence, 50019, Italy.,National Institute of Optics, National Research Council, Florence, 50125, Italy
| | - C Ferrantini
- Division of Physiology, Department of Experimental and Clinical Medicine, University of Florence, Florence, 50134, Italy
| | - R Coppini
- Division of Pharmacology, Department 'NeuroFarBa', University of Florence, Florence, 50139, Italy
| | - P Yan
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, CT, 06030, USA
| | - L M Loew
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, CT, 06030, USA
| | - M Campione
- Neuroscience Institute, National Research Council, Padova, 35121, Italy.,Department of Biomedical Sciences, Univercity ot Padua, Padua, 35121, Italy
| | - L Bocchi
- European Laboratory for Non-Linear Spectroscopy, Florence, 50019, Italy.,Department of Information Engineering, University of Florence, Via S. Marta 3, Florence, 50139, Italy
| | - D Giulietti
- National Institute of Optics, National Research Council, Florence, 50125, Italy.,Department of Physics, University of Pisa, Pisa, 56127, Italy
| | - E Cerbai
- Division of Pharmacology, Department 'NeuroFarBa', University of Florence, Florence, 50139, Italy
| | - C Poggesi
- Division of Physiology, Department of Experimental and Clinical Medicine, University of Florence, Florence, 50134, Italy
| | - G Bub
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - F S Pavone
- European Laboratory for Non-Linear Spectroscopy, Florence, 50019, Italy.,National Institute of Optics, National Research Council, Florence, 50125, Italy.,Department of Physics and Astronomy, University of Florence, Sesto Fiorentino, 50019, Italy
| | - L Sacconi
- European Laboratory for Non-Linear Spectroscopy, Florence, 50019, Italy.,National Institute of Optics, National Research Council, Florence, 50125, Italy
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60
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An adaptive spatio-temporal Gaussian filter for processing cardiac optical mapping data. Comput Biol Med 2018; 102:267-277. [PMID: 29891242 DOI: 10.1016/j.compbiomed.2018.05.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/30/2018] [Accepted: 05/30/2018] [Indexed: 01/25/2023]
Abstract
Optical mapping is widely used as a tool to investigate cardiac electrophysiology in ex vivo preparations. Digital filtering of fluorescence-optical data is an important requirement for robust subsequent data analysis and still a challenge when processing data acquired from thin mammalian myocardium. Therefore, we propose and investigate the use of an adaptive spatio-temporal Gaussian filter for processing optical mapping signals from these kinds of tissue usually having low signal-to-noise ratio (SNR). We demonstrate how filtering parameters can be chosen automatically without additional user input. For systematic comparison of this filter with standard filtering methods from the literature, we generated synthetic signals representing optical recordings from atrial myocardium of a rat heart with varying SNR. Furthermore, all filter methods were applied to experimental data from an ex vivo setup. Our developed filter outperformed the other filter methods regarding local activation time detection at SNRs smaller than 3 dB which are typical noise ratios expected in these signals. At higher SNRs, the proposed filter performed slightly worse than the methods from literature. In conclusion, the proposed adaptive spatio-temporal Gaussian filter is an appropriate tool for investigating fluorescence-optical data with low SNR. The spatio-temporal filter parameters were automatically adapted in contrast to the other investigated filters.
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61
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Broyles CN, Robinson P, Daniels MJ. Fluorescent, Bioluminescent, and Optogenetic Approaches to Study Excitable Physiology in the Single Cardiomyocyte. Cells 2018; 7:cells7060051. [PMID: 29857560 PMCID: PMC6028913 DOI: 10.3390/cells7060051] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 05/22/2018] [Accepted: 05/30/2018] [Indexed: 12/11/2022] Open
Abstract
This review briefly summarizes the single cell application of classical chemical dyes used to visualize cardiomyocyte physiology and their undesirable toxicities which have the potential to confound experimental observations. We will discuss, in detail, the more recent iterative development of fluorescent and bioluminescent protein-based indicators and their emerging application to cardiomyocytes. We will discuss the integration of optical control strategies (optogenetics) to augment the standard imaging approach. This will be done in the context of potential applications, and barriers, of these technologies to disease modelling, drug toxicity, and drug discovery efforts at the single-cell scale.
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Affiliation(s)
- Connor N Broyles
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK.
- BHF Centre of Research Excellence, University of Oxford, Oxford OX3 9DU, UK.
| | - Paul Robinson
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK.
- BHF Centre of Research Excellence, University of Oxford, Oxford OX3 9DU, UK.
| | - Matthew J Daniels
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK.
- BHF Centre of Research Excellence, University of Oxford, Oxford OX3 9DU, UK.
- Department of Cardiology, Oxford University NHS Hospitals Trust, Oxford OX3 9DU, UK.
- BHF Centre of Regenerative Medicine, University of Oxford, Oxford OX3 9DU, UK.
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Mihogaoka 8-1, Ibaraki, 567-0047 Osaka, Japan.
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62
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Shaheen N, Shiti A, Huber I, Shinnawi R, Arbel G, Gepstein A, Setter N, Goldfracht I, Gruber A, Chorna SV, Gepstein L. Human Induced Pluripotent Stem Cell-Derived Cardiac Cell Sheets Expressing Genetically Encoded Voltage Indicator for Pharmacological and Arrhythmia Studies. Stem Cell Reports 2018; 10:1879-1894. [PMID: 29754959 PMCID: PMC5989818 DOI: 10.1016/j.stemcr.2018.04.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 04/11/2018] [Accepted: 04/12/2018] [Indexed: 12/18/2022] Open
Abstract
Fulfilling the potential of human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes for studying conduction and arrhythmogenesis requires development of multicellular models and methods for long-term repeated tissue phenotyping. We generated confluent hiPSC-derived cardiac cell sheets (hiPSC-CCSs), expressing the genetically encoded voltage indicator ArcLight. ArcLight-based optical mapping allowed generation of activation and action-potential duration (APD) maps, which were validated by mapping the same hiPSC-CCSs with the voltage-sensitive dye, Di-4-ANBDQBS. ArcLight mapping allowed long-term assessment of electrical remodeling in the hiPSC-CCSs and evaluation of drug-induced conduction slowing (carbenoxolone, lidocaine, and quinidine) and APD prolongation (quinidine and dofetilide). The latter studies also enabled step-by-step depiction of drug-induced arrhythmogenesis ("torsades de pointes in the culture dish") and its prevention by MgSO4 and rapid pacing. Phase-mapping analysis allowed biophysical characterization of spiral waves induced in the hiPSC-CCSs and their termination by electrical cardioversion and overdrive pacing. In conclusion, ArcLight mapping of hiPSC-CCSs provides a powerful tool for drug testing and arrhythmia investigation. Optical mapping of hiPSC-derived cardiac cell sheets expressing ArcLight Evaluating effects of drugs and time (weeks) on conduction and APD Mapping drug-induced TdP and electrically induced spiral waves (rotors) Evaluating interventions aiming to prevent or terminate arrhythmias in the model
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Affiliation(s)
- Naim Shaheen
- Sohnis Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel, POB 9649, Haifa 3109601, Israel
| | - Assad Shiti
- Sohnis Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel, POB 9649, Haifa 3109601, Israel
| | - Irit Huber
- Sohnis Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel, POB 9649, Haifa 3109601, Israel
| | - Rami Shinnawi
- Sohnis Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel, POB 9649, Haifa 3109601, Israel
| | - Gil Arbel
- Sohnis Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel, POB 9649, Haifa 3109601, Israel
| | - Amira Gepstein
- Sohnis Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel, POB 9649, Haifa 3109601, Israel
| | - Noga Setter
- Sohnis Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel, POB 9649, Haifa 3109601, Israel
| | - Idit Goldfracht
- Sohnis Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel, POB 9649, Haifa 3109601, Israel
| | - Amit Gruber
- Sohnis Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel, POB 9649, Haifa 3109601, Israel
| | - Snizhanna V Chorna
- Sohnis Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel, POB 9649, Haifa 3109601, Israel
| | - Lior Gepstein
- Sohnis Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel, POB 9649, Haifa 3109601, Israel; Cardiolology Department, Rambam Health Care Campus, Haliya Hashniya St 8, Haifa 3109601, Israel.
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63
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Streit J, Kleinlogel S. Dynamic all-optical drug screening on cardiac voltage-gated ion channels. Sci Rep 2018; 8:1153. [PMID: 29348631 PMCID: PMC5773578 DOI: 10.1038/s41598-018-19412-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 12/27/2017] [Indexed: 11/09/2022] Open
Abstract
Voltage-gated ion channels (VGCs) are prime targets for the pharmaceutical industry, but drug profiling on VGCs is challenging, since drug interactions are confined to specific conformational channel states mediated by changes in transmembrane potential. Here we combined various optogenetic tools to develop dynamic, high-throughput drug profiling assays with defined light-step protocols to interrogate VGC states on a millisecond timescale. We show that such light-induced electrophysiology (LiEp) yields high-quality pharmacological data with exceptional screening windows for drugs acting on the major cardiac VGCs, including hNav1.5, hKv1.5 and hERG. LiEp-based screening remained robust when using a variety of optogenetic actuators (ChR2, ChR2(H134R), CatCh, ChR2-EYFP-βArchT) and different types of organic (RH421, Di-4-ANBDQPQ, BeRST1) or genetic voltage sensors (QuasAr1). The tractability of LiEp allows a versatile and precise alternative to state-of-the-art VGC drug screening platforms such as automated electrophysiology or FLIPR readers.
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Affiliation(s)
- Jonas Streit
- Institute of Physiology, University of Bern, Bühlplatz 5, 3012, Bern, Switzerland
| | - Sonja Kleinlogel
- Institute of Physiology, University of Bern, Bühlplatz 5, 3012, Bern, Switzerland.
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64
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McPheeters MT, Wang YT, Werdich AA, Jenkins MW, Laurita KR. An infrared optical pacing system for screening cardiac electrophysiology in human cardiomyocytes. PLoS One 2017; 12:e0183761. [PMID: 28837652 PMCID: PMC5570338 DOI: 10.1371/journal.pone.0183761] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 08/10/2017] [Indexed: 01/05/2023] Open
Abstract
Human cardiac myocytes derived from pluripotent stem cells (hCM) have invigorated interest in genetic disease mechanisms and cardiac safety testing; however, the technology to fully assess electrophysiological function in an assay that is amenable to high throughput screening has lagged. We describe a fully contactless system using optical pacing with an infrared (IR) laser and multi-site high fidelity fluorescence imaging to assess multiple electrophysiological parameters from hCM monolayers in a standard 96-well plate. Simultaneous multi-site action potentials (FluoVolt) or Ca2+ transients (Fluo4-AM) were measured, from which high resolution maps of conduction velocity and action potential duration (APD) were obtained in a single well. Energy thresholds for optical pacing were determined for cell plating density, laser spot size, pulse width, and wavelength and found to be within ranges reported previously for reliable pacing. Action potentials measured using FluoVolt and a microelectrode exhibited the same morphology and rate of depolarization. Importantly, we show that this can be achieved accurately with minimal damage to hCM due to optical pacing or fluorescence excitation. Finally, using this assay we demonstrate that hCM exhibit reproducible changes in repolarization and impulse conduction velocity for Flecainide and Quinidine, two well described reference compounds. In conclusion, we demonstrate a high fidelity electrophysiological screening assay that incorporates optical pacing with IR light to control beating rate of hCM monolayers.
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Affiliation(s)
- Matthew T. McPheeters
- Pediatrics, Case Western Reserve University, Cleveland, Ohio, United States of America
- Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Yves T. Wang
- Pediatrics, Case Western Reserve University, Cleveland, Ohio, United States of America
- Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Andreas A. Werdich
- Brigham and Women's Hospital/Harvard Medical School, Cardiovascular Division, Boston, Massachusetts, United States of America
| | - Michael W. Jenkins
- Pediatrics, Case Western Reserve University, Cleveland, Ohio, United States of America
- Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Kenneth R. Laurita
- Brigham and Women's Hospital/Harvard Medical School, Cardiovascular Division, Boston, Massachusetts, United States of America
- Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, United States of America
- Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
- * E-mail:
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65
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Costantino AJ, Hyatt CJ, Kollisch-Singule MC, Beaumont J, Roth BJ, Pertsov AM. Determining the light scattering and absorption parameters from forward-directed flux measurements in cardiac tissue. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:76009. [PMID: 28715543 DOI: 10.1117/1.jbo.22.7.076009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 06/15/2017] [Indexed: 06/07/2023]
Abstract
We describe a method to accurately measure the light scattering model parameters from forward-directed flux (FDF) measurements carried out with a fiber-optic probe (optrode). Improved determination of light scattering parameters will, in turn, permit better modeling and interpretation of optical mapping in the heart using voltage-sensitive dyes. Using our optrode-based system, we carried out high spatial resolution measurements of FDF in intact and homogenized cardiac tissue, as well as in intralipid-based tissue phantoms. The samples were illuminated with a broad collimated beam at 660 and 532 nm. Measurements were performed with a plunge fiber-optic probe (NA=0.22) at a spatial resolution of up to 10 μm. In the vicinity of the illuminated surface, the FDF consistently manifested a fast decaying exponent with a space constant comparable with the decay rate of ballistic photons. Using a Monte Carlo model, we obtained a simple empirical formula linking the rate of the fast exponent to the scattering coefficient, the anisotropy parameter g, and the numerical aperture of the probe. The estimates of scattering coefficient based on this formula were validated in tissue phantoms. Potential applications of optical fiber-based FDF measurements for the evaluation of optical parameters in turbid media are discussed.
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Affiliation(s)
- Anthony J Costantino
- Binghamton University, Department of Electrical and Computer Engineering, Binghamton, New York, United States
| | - Christopher J Hyatt
- Springfield College, Department of Mathematics, Physics and Computer Science, Springfield, Massachusetts, United States
| | | | - Jacques Beaumont
- Upstate Medical University, Department of Pharmacology, Syracuse, New York, United States
| | - Bradley J Roth
- Oakland University, Department of Physics, Rochester, Michigan, United States
| | - Arkady M Pertsov
- Upstate Medical University, Department of Pharmacology, Syracuse, New York, United States
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66
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Zhang H, Iijima K, Huang J, Walcott GP, Rogers JM. Optical Mapping of Membrane Potential and Epicardial Deformation in Beating Hearts. Biophys J 2017; 111:438-451. [PMID: 27463145 DOI: 10.1016/j.bpj.2016.03.043] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 03/01/2016] [Accepted: 03/24/2016] [Indexed: 11/26/2022] Open
Abstract
Cardiac optical mapping uses potentiometric fluorescent dyes to image membrane potential (Vm). An important limitation of conventional optical mapping is that contraction is usually arrested pharmacologically to prevent motion artifacts from obscuring Vm signals. However, these agents may alter electrophysiology, and by abolishing contraction, also prevent optical mapping from being used to study coupling between electrical and mechanical function. Here, we present a method to simultaneously map Vm and epicardial contraction in the beating heart. Isolated perfused swine hearts were stained with di-4-ANEPPS and fiducial markers were glued to the epicardium for motion tracking. The heart was imaged at 750 Hz with a video camera. Fluorescence was excited with cyan or blue LEDs on alternating camera frames, thus providing a 375-Hz effective sampling rate. Marker tracking enabled the pixel(s) imaging any epicardial site within the marked region to be identified in each camera frame. Cyan- and blue-elicited fluorescence have different sensitivities to Vm, but other signal features, primarily motion artifacts, are common. Thus, taking the ratio of fluorescence emitted by a motion-tracked epicardial site in adjacent frames removes artifacts, leaving Vm (excitation ratiometry). Reconstructed Vm signals were validated by comparison to monophasic action potentials and to conventional optical mapping signals. Binocular imaging with additional video cameras enabled marker motion to be tracked in three dimensions. From these data, epicardial deformation during the cardiac cycle was quantified by computing finite strain fields. We show that the method can simultaneously map Vm and strain in a left-sided working heart preparation and can image changes in both electrical and mechanical function 5 min after the induction of regional ischemia. By allowing high-resolution optical mapping in the absence of electromechanical uncoupling agents, the method relieves a long-standing limitation of optical mapping and has potential to enhance new studies in coupled cardiac electromechanics.
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Affiliation(s)
- Hanyu Zhang
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Kenichi Iijima
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jian Huang
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Gregory P Walcott
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jack M Rogers
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama.
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67
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Quantitative assessment of passive electrical properties of the cardiac T-tubular system by FRAP microscopy. Proc Natl Acad Sci U S A 2017; 114:5737-5742. [PMID: 28507142 DOI: 10.1073/pnas.1702188114] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Well-coordinated activation of all cardiomyocytes must occur on every heartbeat. At the cell level, a complex network of sarcolemmal invaginations, called the transverse-axial tubular system (TATS), propagates membrane potential changes to the cell core, ensuring synchronous and uniform excitation-contraction coupling. Although myocardial conduction of excitation has been widely described, the electrical properties of the TATS remain mostly unknown. Here, we exploit the formal analogy between diffusion and electrical conductivity to link the latter with the diffusional properties of TATS. Fluorescence recovery after photobleaching (FRAP) microscopy is used to probe the diffusion properties of TATS in isolated rat cardiomyocytes: A fluorescent dextran inside TATS lumen is photobleached, and signal recovery by diffusion of unbleached dextran from the extracellular space is monitored. We designed a mathematical model to correlate the time constant of fluorescence recovery with the apparent diffusion coefficient of the fluorescent molecules. Then, apparent diffusion is linked to electrical conductivity and used to evaluate the efficiency of the passive spread of membrane depolarization along TATS. The method is first validated in cells where most TATS elements are acutely detached by osmotic shock and then applied to probe TATS electrical conductivity in failing heart cells. We find that acute and pathological tubular remodeling significantly affect TATS electrical conductivity. This may explain the occurrence of defects in action potential propagation at the level of single T-tubules, recently observed in diseased cardiomyocytes.
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68
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Crocini C, Ferrantini C, Pavone FS, Sacconi L. Optogenetics gets to the heart: A guiding light beyond defibrillation. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2017; 130:132-139. [PMID: 28506694 DOI: 10.1016/j.pbiomolbio.2017.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 05/10/2017] [Accepted: 05/11/2017] [Indexed: 01/01/2023]
Abstract
Optogenetics provides a tool for controlling the electrical activity of excitable cells by means of the interaction of light with light-gated ion channels. Despite the fact that optogenetics has been intensively utilized in the neurosciences, it has been more rarely employed as an instrument for studying cardiac pathophysiology. However, the advantages of optical approaches to perturb cardiac electrical activity are numerous, especially when the spatio-temporal qualities of light are utterly exploited. Here, we review the main breakthroughs employing optogenetics to perturb cardiac pathophysiology and attempt a comparison of methods and procedures that have employed optogenetics in the heart. We particularly focus on light-based defibrillation strategies that represent one of the latest achievements in this field. We highlight the important role of advanced optical methods for detecting and stimulating electrical activity for optimizing defibrillation strategies and, more generally, for dissecting novel insights in cardiac physiology. Finally, we discuss the main future perspectives that we envision for optogenetics in the heart, both in terms of translational applications and for addressing fundamental questions of cardiac function.
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Affiliation(s)
- Claudia Crocini
- European Laboratory for Non Linear Spectroscopy (LENS), Via Nello Carrara, 1 - 50019 Sesto Fiorentino, FI, Italy; National Institute of Optic (CNR-INO), Via Nello Carrara, 1 - 50019 Sesto Fiorentino, Italy.
| | - Cecilia Ferrantini
- Division of Physiology, Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Francesco S Pavone
- European Laboratory for Non Linear Spectroscopy (LENS), Via Nello Carrara, 1 - 50019 Sesto Fiorentino, FI, Italy; National Institute of Optic (CNR-INO), Via Nello Carrara, 1 - 50019 Sesto Fiorentino, Italy; Department of Physics and Astronomy, University of Florence, 50019 Sesto Fiorentino, Italy
| | - Leonardo Sacconi
- European Laboratory for Non Linear Spectroscopy (LENS), Via Nello Carrara, 1 - 50019 Sesto Fiorentino, FI, Italy; National Institute of Optic (CNR-INO), Via Nello Carrara, 1 - 50019 Sesto Fiorentino, Italy
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69
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Abbott J, Ye T, Qin L, Jorgolli M, Gertner RS, Ham D, Park H. CMOS nanoelectrode array for all-electrical intracellular electrophysiological imaging. NATURE NANOTECHNOLOGY 2017; 12:460-466. [PMID: 28192391 DOI: 10.1038/nnano.2017.3] [Citation(s) in RCA: 138] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 01/06/2017] [Indexed: 05/18/2023]
Abstract
Developing a new tool capable of high-precision electrophysiological recording of a large network of electrogenic cells has long been an outstanding challenge in neurobiology and cardiology. Here, we combine nanoscale intracellular electrodes with complementary metal-oxide-semiconductor (CMOS) integrated circuits to realize a high-fidelity all-electrical electrophysiological imager for parallel intracellular recording at the network level. Our CMOS nanoelectrode array has 1,024 recording/stimulation 'pixels' equipped with vertical nanoelectrodes, and can simultaneously record intracellular membrane potentials from hundreds of connected in vitro neonatal rat ventricular cardiomyocytes. We demonstrate that this network-level intracellular recording capability can be used to examine the effect of pharmaceuticals on the delicate dynamics of a cardiomyocyte network, thus opening up new opportunities in tissue-based pharmacological screening for cardiac and neuronal diseases as well as fundamental studies of electrogenic cells and their networks.
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Affiliation(s)
- Jeffrey Abbott
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Tianyang Ye
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Ling Qin
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Marsela Jorgolli
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Rona S Gertner
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Donhee Ham
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Hongkun Park
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, Massachusetts 02142, USA
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70
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Low-Cost Optical Mapping Systems for Panoramic Imaging of Complex Arrhythmias and Drug-Action in Translational Heart Models. Sci Rep 2017; 7:43217. [PMID: 28240274 PMCID: PMC5327492 DOI: 10.1038/srep43217] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 01/20/2017] [Indexed: 01/29/2023] Open
Abstract
Panoramic optical mapping is the primary method for imaging electrophysiological activity from the entire outer surface of Langendorff-perfused hearts. To date, it is the only method of simultaneously measuring multiple key electrophysiological parameters, such as transmembrane voltage and intracellular free calcium, at high spatial and temporal resolution. Despite the impact it has already had on the fields of cardiac arrhythmias and whole-heart computational modeling, present-day system designs precludes its adoption by the broader cardiovascular research community because of their high costs. Taking advantage of recent technological advances, we developed and validated low-cost optical mapping systems for panoramic imaging using Langendorff-perfused pig hearts, a clinically-relevant model in basic research and bioengineering. By significantly lowering financial thresholds, this powerful cardiac electrophysiology imaging modality may gain wider use in research and, even, teaching laboratories, which we substantiated using the lower-cost Langendorff-perfused rabbit heart model.
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71
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Electrotonic coupling of excitable and nonexcitable cells in the heart revealed by optogenetics. Proc Natl Acad Sci U S A 2016; 113:14852-14857. [PMID: 27930302 DOI: 10.1073/pnas.1611184114] [Citation(s) in RCA: 152] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Electrophysiological studies of excitable organs usually focus on action potential (AP)-generating cells, whereas nonexcitable cells are generally considered as barriers to electrical conduction. Whether nonexcitable cells may modulate excitable cell function or even contribute to AP conduction via direct electrotonic coupling to AP-generating cells is unresolved in the heart: such coupling is present in vitro, but conclusive evidence in situ is lacking. We used genetically encoded voltage-sensitive fluorescent protein 2.3 (VSFP2.3) to monitor transmembrane potential in either myocytes or nonmyocytes of murine hearts. We confirm that VSFP2.3 allows measurement of cell type-specific electrical activity. We show that VSFP2.3, expressed solely in nonmyocytes, can report cardiomyocyte AP-like signals at the border of healed cryoinjuries. Using EM-based tomographic reconstruction, we further discovered tunneling nanotube connections between myocytes and nonmyocytes in cardiac scar border tissue. Our results provide direct electrophysiological evidence of heterocellular electrotonic coupling in native myocardium and identify tunneling nanotubes as a possible substrate for electrical cell coupling that may be in addition to previously discovered connexins at sites of myocyte-nonmyocyte contact in the heart. These findings call for reevaluation of cardiac nonmyocyte roles in electrical connectivity of the heterocellular heart.
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72
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Stoyek MR, Quinn TA, Croll RP, Smith FM. Zebrafish heart as a model to study the integrative autonomic control of pacemaker function. Am J Physiol Heart Circ Physiol 2016; 311:H676-88. [PMID: 27342878 DOI: 10.1152/ajpheart.00330.2016] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 06/23/2016] [Indexed: 01/01/2023]
Abstract
The cardiac pacemaker sets the heart's primary rate, with pacemaker discharge controlled by the autonomic nervous system through intracardiac ganglia. A fundamental issue in understanding the relationship between neural activity and cardiac chronotropy is the identification of neuronal populations that control pacemaker cells. To date, most studies of neurocardiac control have been done in mammalian species, where neurons are embedded in and distributed throughout the heart, so they are largely inaccessible for whole-organ, integrative studies. Here, we establish the isolated, innervated zebrafish heart as a novel alternative model for studies of autonomic control of heart rate. Stimulation of individual cardiac vagosympathetic nerve trunks evoked bradycardia (parasympathetic activation) and tachycardia (sympathetic activation). Simultaneous stimulation of both vagosympathetic nerve trunks evoked a summative effect. Effects of nerve stimulation were mimicked by direct application of cholinergic and adrenergic agents. Optical mapping of electrical activity confirmed the sinoatrial region as the site of origin of normal pacemaker activity and identified a secondary pacemaker in the atrioventricular region. Strong vagosympathetic nerve stimulation resulted in a shift in the origin of initial excitation from the sinoatrial pacemaker to the atrioventricular pacemaker. Putative pacemaker cells in the sinoatrial and atrioventricular regions expressed adrenergic β2 and cholinergic muscarinic type 2 receptors. Collectively, we have demonstrated that the zebrafish heart contains the accepted hallmarks of vertebrate cardiac control, establishing this preparation as a viable model for studies of integrative physiological control of cardiac function by intracardiac neurons.
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Affiliation(s)
- Matthew R Stoyek
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada; and
| | - T Alexander Quinn
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Roger P Croll
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Frank M Smith
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada; and
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73
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Klimas A, Ambrosi CM, Yu J, Williams JC, Bien H, Entcheva E. OptoDyCE as an automated system for high-throughput all-optical dynamic cardiac electrophysiology. Nat Commun 2016; 7:11542. [PMID: 27161419 PMCID: PMC4866323 DOI: 10.1038/ncomms11542] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Accepted: 04/05/2016] [Indexed: 01/11/2023] Open
Abstract
The improvement of preclinical cardiotoxicity testing, discovery of new ion-channel-targeted drugs, and phenotyping and use of stem cell-derived cardiomyocytes and other biologics all necessitate high-throughput (HT), cellular-level electrophysiological interrogation tools. Optical techniques for actuation and sensing provide instant parallelism, enabling contactless dynamic HT testing of cells and small-tissue constructs, not affordable by other means. Here we show, computationally and experimentally, the limits of all-optical electrophysiology when applied to drug testing, then implement and validate OptoDyCE, a fully automated system for all-optical cardiac electrophysiology. We validate optical actuation by virally introducing optogenetic drivers in rat and human cardiomyocytes or through the modular use of dedicated light-sensitive somatic ‘spark' cells. We show that this automated all-optical approach provides HT means of cellular interrogation, that is, allows for dynamic testing of >600 multicellular samples or compounds per hour, and yields high-content information about the action of a drug over time, space and doses. The efficiency of preclinical drug testing and characterization of cellular function can be improved through the use of optogenetic tools. Here Klimas et al. present and validate OptoDyCE, a fully automated system for all-optical high-throughput cardiac electrophysiology.
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Affiliation(s)
- Aleksandra Klimas
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Christina M Ambrosi
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Jinzhu Yu
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - John C Williams
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Harold Bien
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Emilia Entcheva
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
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74
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Jaimes R, Walton RD, Pasdois P, Bernus O, Efimov IR, Kay MW. A technical review of optical mapping of intracellular calcium within myocardial tissue. Am J Physiol Heart Circ Physiol 2016; 310:H1388-401. [PMID: 27016580 DOI: 10.1152/ajpheart.00665.2015] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 03/21/2016] [Indexed: 12/18/2022]
Abstract
Optical mapping of Ca(2+)-sensitive fluorescence probes has become an extremely useful approach and adopted by many cardiovascular research laboratories to study a spectrum of myocardial physiology and disease conditions. Optical mapping data are often displayed as detailed pseudocolor images, providing unique insight for interpreting mechanisms of ectopic activity, action potential and Ca(2+) transient alternans, tachycardia, and fibrillation. Ca(2+)-sensitive fluorescent probes and optical mapping systems continue to evolve in the ongoing effort to improve therapies that ease the growing worldwide burden of cardiovascular disease. In this technical review we provide an updated overview of conventional approaches for optical mapping of Cai (2+) within intact myocardium. In doing so, a brief history of Cai (2+) probes is provided, and nonratiometric and ratiometric Ca(2+) probes are discussed, including probes for imaging sarcoplasmic reticulum Ca(2+) and probes compatible with potentiometric dyes for dual optical mapping. Typical measurements derived from optical Cai (2+) signals are explained, and the analytics used to compute them are presented. Last, recent studies using Cai (2+) optical mapping to study arrhythmias, heart failure, and metabolic perturbations are summarized.
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Affiliation(s)
- Rafael Jaimes
- Department of Biomedical Engineering, The George Washington University. Washington, District of Columbia
| | - Richard D Walton
- Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France; Institut National de la Santé et de la Recherche Médicale, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France; and L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Université de Bordeaux, Bordeaux, France
| | - Philippe Pasdois
- Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France; Institut National de la Santé et de la Recherche Médicale, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France; and L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Université de Bordeaux, Bordeaux, France
| | - Olivier Bernus
- Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France; Institut National de la Santé et de la Recherche Médicale, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France; and L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Université de Bordeaux, Bordeaux, France
| | - Igor R Efimov
- Department of Biomedical Engineering, The George Washington University. Washington, District of Columbia; L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Université de Bordeaux, Bordeaux, France
| | - Matthew W Kay
- Department of Biomedical Engineering, The George Washington University. Washington, District of Columbia;
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Huang YL, Walker AS, Miller EW. A Photostable Silicon Rhodamine Platform for Optical Voltage Sensing. J Am Chem Soc 2015; 137:10767-76. [PMID: 26237573 DOI: 10.1021/jacs.5b06644] [Citation(s) in RCA: 153] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
This paper describes the design and synthesis of a photostable, far-red to near-infrared (NIR) platform for optical voltage sensing. We developed a new, sulfonated silicon rhodamine fluorophore and integrated it with a phenylenevinylene molecular wire to create a Berkeley Red Sensor of Transmembrane potential, or BeRST 1 ("burst"). BeRST 1 is the first member of a class of far-red to NIR voltage sensitive dyes that make use of a photoinduced electron transfer (PeT) trigger for optical interrogation of membrane voltage. We show that BeRST 1 displays bright, membrane-localized fluorescence in living cells, high photostability, and excellent voltage sensitivity in neurons. Depolarization of the plasma membrane results in rapid fluorescence increases (24% ΔF/F per 100 mV). BeRST 1 can be used in conjunction with fluorescent stains for organelles, Ca(2+) indicators, and voltage-sensitive fluorescent proteins. In addition, the red-shifted spectral profile of BeRST 1, relative to commonly employed optogenetic actuators like ChannelRhodopsin2 (ChR2), which require blue light, enables optical electrophysiology in neurons. The high speed, sensitivity, photostability and long-wavelength fluorescence profiles of BeRST 1 make it a useful platform for the noninvasive, optical dissection of neuronal activity.
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Affiliation(s)
- Yi-Lin Huang
- Departments of Chemistry, ‡Molecular & Cell Biology, and §Helen Wills Neuroscience Institute, University of California , Berkeley, California 94720, United States
| | - Alison S Walker
- Departments of Chemistry, ‡Molecular & Cell Biology, and §Helen Wills Neuroscience Institute, University of California , Berkeley, California 94720, United States
| | - Evan W Miller
- Departments of Chemistry, ‡Molecular & Cell Biology, and §Helen Wills Neuroscience Institute, University of California , Berkeley, California 94720, United States
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76
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Optical Imaging of Cardiac Action Potential. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 859:299-311. [PMID: 26238058 DOI: 10.1007/978-3-319-17641-3_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This chapter reviews the major milestones and scientific achievements facilitated by optical imaging of the action potential in the heart over more than four decades since its introduction. We discuss the limitations of this technique, which sometimes are not fully recognized; the unresolved issues, such as motion artifacts, and the newest developments and future directions.
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Chang Liao ML, de Boer TP, Mutoh H, Raad N, Richter C, Wagner E, Downie BR, Unsöld B, Arooj I, Streckfuss-Bömeke K, Döker S, Luther S, Guan K, Wagner S, Lehnart SE, Maier LS, Stühmer W, Wettwer E, van Veen T, Morlock MM, Knöpfel T, Zimmermann WH. Sensing Cardiac Electrical Activity With a Cardiac Myocyte--Targeted Optogenetic Voltage Indicator. Circ Res 2015; 117:401-12. [PMID: 26078285 DOI: 10.1161/circresaha.117.306143] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 06/15/2015] [Indexed: 01/17/2023]
Abstract
RATIONALE Monitoring and controlling cardiac myocyte activity with optogenetic tools offer exciting possibilities for fundamental and translational cardiovascular research. Genetically encoded voltage indicators may be particularly attractive for minimal invasive and repeated assessments of cardiac excitation from the cellular to the whole heart level. OBJECTIVE To test the hypothesis that cardiac myocyte-targeted voltage-sensitive fluorescence protein 2.3 (VSFP2.3) can be exploited as optogenetic tool for the monitoring of electric activity in isolated cardiac myocytes and the whole heart as well as function and maturity in induced pluripotent stem cell-derived cardiac myocytes. METHODS AND RESULTS We first generated mice with cardiac myocyte-restricted expression of VSFP2.3 and demonstrated distinct localization of VSFP2.3 at the t-tubulus/junctional sarcoplasmic reticulum microdomain without any signs for associated pathologies (assessed by echocardiography, RNA-sequencing, and patch clamping). Optically recorded VSFP2.3 signals correlated well with membrane voltage measured simultaneously by patch clamping. The use of VSFP2.3 for human action potential recordings was confirmed by simulation of immature and mature action potentials in murine VSFP2.3 cardiac myocytes. Optical cardiograms could be monitored in whole hearts ex vivo and minimally invasively in vivo via fiber optics at physiological heart rate (10 Hz) and under pacing-induced arrhythmia. Finally, we reprogrammed tail-tip fibroblasts from transgenic mice and used the VSFP2.3 sensor for benchmarking functional and structural maturation in induced pluripotent stem cell-derived cardiac myocytes. CONCLUSIONS We introduce a novel transgenic voltage-sensor model as a new method in cardiovascular research and provide proof of concept for its use in optogenetic sensing of physiological and pathological excitation in mature and immature cardiac myocytes in vitro and in vivo.
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Affiliation(s)
- Mei-Ling Chang Liao
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Teun P de Boer
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Hiroki Mutoh
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Nour Raad
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Claudia Richter
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Eva Wagner
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Bryan R Downie
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Bernhard Unsöld
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Iqra Arooj
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Katrin Streckfuss-Bömeke
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Stephan Döker
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Stefan Luther
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Kaomei Guan
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Stefan Wagner
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Stephan E Lehnart
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Lars S Maier
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Walter Stühmer
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Erich Wettwer
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Toon van Veen
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Michael M Morlock
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Thomas Knöpfel
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.)
| | - Wolfram-Hubertus Zimmermann
- From the Institute of Pharmacology (M.-L.C.L., S.D., E. Wettwer, W.-H.Z.), Clinic for Cardiology and Pulmonology (N.R., E. Wagner, B.U., K.S.-B., K.G., S.W., S.E.L., L.S.M.), and Microarray and Deep-Sequencing Facility (B.R.D.), University Medical Center Göttingen, Göttingen, Germany; DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany (M.-L.C.L., N.R., E. Wagner, K.S.-B., S.L., K.G., S.E.L., W.S., W.-H.Z.); Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany (M.-L.C.L., M.M.M.); Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands (T.P.d.B., I.A., T.v.V.); Laboratory of Neuronal Circuit Dynamics, RIKEN Brain Science Institute, Saitama, Japan (H.M., T.K.); Max-Planck-Institutes for Dynamics and Self Organization (N.R., C.R., S.L.) and Experimental Medicine (W.S.), Göttingen, Germany; Department of Internal Medicine II, University Hospital of Regensburg, Regensburg, Germany (B.U., S.W., L.S.M.); Department of Medicine and Centre for Neurotechnology, Imperial College London, United Kingdom (T.K.).
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Gutbrod SR, Walton R, Gilbert S, Meillet V, Jaïs P, Hocini M, Haïssaguerre M, Dubois R, Bernus O, Efimov IR. Quantification of the transmural dynamics of atrial fibrillation by simultaneous endocardial and epicardial optical mapping in an acute sheep model. Circ Arrhythm Electrophysiol 2015; 8:456-65. [PMID: 25713215 DOI: 10.1161/circep.114.002545] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 02/09/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND Therapy strategies for atrial fibrillation based on electric characterization are becoming viable personalized medicine approaches to treat a notoriously difficult disease. In light of these approaches that rely on high-density surface mapping, this study aims to evaluate the presence of 3-dimensional electric substrate variations within the transmural wall during acute episodes of atrial fibrillation. METHODS AND RESULTS Optical signals were simultaneously acquired from the epicardial and endocardial tissue during acute fibrillation in ovine isolated left atria. Dominant frequency, regularity index, propagation angles, and phase dynamics were assessed and correlated across imaging planes to gauge the synchrony of the activation patterns compared with paced rhythms. Static frequency parameters were well correlated spatially between the endocardium and the epicardium (dominant frequency, 0.79 ± 0.06 and regularity index, 0.93 ± 0.009). However, dynamic tracking of propagation vectors and phase singularity trajectories revealed discordant activity across the transmural wall. The absolute value of the difference in the number, spatial stability, and temporal stability of phase singularities between the epicardial and the endocardial planes was significantly >0 with a median difference of 1.0, 9.27%, and 19.75%, respectively. The number of wavefronts with respect to time was significantly less correlated and the difference in propagation angle was significantly larger in fibrillation compared with paced rhythms. CONCLUSIONS Atrial fibrillation substrates are dynamic 3-dimensional structures with a range of discordance between the epicardial and the endocardial tissue. The results of this study suggest that transmural propagation may play a role in atrial fibrillation maintenance mechanisms.
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Affiliation(s)
- Sarah R Gutbrod
- From the Department of Biomedical Engineering, Washington University in Saint Louis, MO (S.R.G., I.R.E.); L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Université de Bordeaux, France (S.R.G., R.W., S.G., V.M., P.J., M.H., M.H., R.D., O.B., I.R.E.); Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); CHU de Bordeaux, Hôpital du Haut Lévêque, Pessac, France (V.M., P.J., M.H., M.H.); and Max Delbrück Center for Molecular Medicine, Berlin, Germany (S.G.)
| | - Richard Walton
- From the Department of Biomedical Engineering, Washington University in Saint Louis, MO (S.R.G., I.R.E.); L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Université de Bordeaux, France (S.R.G., R.W., S.G., V.M., P.J., M.H., M.H., R.D., O.B., I.R.E.); Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); CHU de Bordeaux, Hôpital du Haut Lévêque, Pessac, France (V.M., P.J., M.H., M.H.); and Max Delbrück Center for Molecular Medicine, Berlin, Germany (S.G.)
| | - Stephen Gilbert
- From the Department of Biomedical Engineering, Washington University in Saint Louis, MO (S.R.G., I.R.E.); L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Université de Bordeaux, France (S.R.G., R.W., S.G., V.M., P.J., M.H., M.H., R.D., O.B., I.R.E.); Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); CHU de Bordeaux, Hôpital du Haut Lévêque, Pessac, France (V.M., P.J., M.H., M.H.); and Max Delbrück Center for Molecular Medicine, Berlin, Germany (S.G.)
| | - Valentin Meillet
- From the Department of Biomedical Engineering, Washington University in Saint Louis, MO (S.R.G., I.R.E.); L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Université de Bordeaux, France (S.R.G., R.W., S.G., V.M., P.J., M.H., M.H., R.D., O.B., I.R.E.); Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); CHU de Bordeaux, Hôpital du Haut Lévêque, Pessac, France (V.M., P.J., M.H., M.H.); and Max Delbrück Center for Molecular Medicine, Berlin, Germany (S.G.)
| | - Pierre Jaïs
- From the Department of Biomedical Engineering, Washington University in Saint Louis, MO (S.R.G., I.R.E.); L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Université de Bordeaux, France (S.R.G., R.W., S.G., V.M., P.J., M.H., M.H., R.D., O.B., I.R.E.); Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); CHU de Bordeaux, Hôpital du Haut Lévêque, Pessac, France (V.M., P.J., M.H., M.H.); and Max Delbrück Center for Molecular Medicine, Berlin, Germany (S.G.)
| | - Mélèze Hocini
- From the Department of Biomedical Engineering, Washington University in Saint Louis, MO (S.R.G., I.R.E.); L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Université de Bordeaux, France (S.R.G., R.W., S.G., V.M., P.J., M.H., M.H., R.D., O.B., I.R.E.); Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); CHU de Bordeaux, Hôpital du Haut Lévêque, Pessac, France (V.M., P.J., M.H., M.H.); and Max Delbrück Center for Molecular Medicine, Berlin, Germany (S.G.)
| | - Michel Haïssaguerre
- From the Department of Biomedical Engineering, Washington University in Saint Louis, MO (S.R.G., I.R.E.); L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Université de Bordeaux, France (S.R.G., R.W., S.G., V.M., P.J., M.H., M.H., R.D., O.B., I.R.E.); Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); CHU de Bordeaux, Hôpital du Haut Lévêque, Pessac, France (V.M., P.J., M.H., M.H.); and Max Delbrück Center for Molecular Medicine, Berlin, Germany (S.G.)
| | - Rémi Dubois
- From the Department of Biomedical Engineering, Washington University in Saint Louis, MO (S.R.G., I.R.E.); L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Université de Bordeaux, France (S.R.G., R.W., S.G., V.M., P.J., M.H., M.H., R.D., O.B., I.R.E.); Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); CHU de Bordeaux, Hôpital du Haut Lévêque, Pessac, France (V.M., P.J., M.H., M.H.); and Max Delbrück Center for Molecular Medicine, Berlin, Germany (S.G.)
| | - Olivier Bernus
- From the Department of Biomedical Engineering, Washington University in Saint Louis, MO (S.R.G., I.R.E.); L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Université de Bordeaux, France (S.R.G., R.W., S.G., V.M., P.J., M.H., M.H., R.D., O.B., I.R.E.); Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); CHU de Bordeaux, Hôpital du Haut Lévêque, Pessac, France (V.M., P.J., M.H., M.H.); and Max Delbrück Center for Molecular Medicine, Berlin, Germany (S.G.)
| | - Igor R Efimov
- From the Department of Biomedical Engineering, Washington University in Saint Louis, MO (S.R.G., I.R.E.); L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Université de Bordeaux, France (S.R.G., R.W., S.G., V.M., P.J., M.H., M.H., R.D., O.B., I.R.E.); Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, Bordeaux, France (R.W., V.M., P.J., M.H., M.H., R.D., O.B.); CHU de Bordeaux, Hôpital du Haut Lévêque, Pessac, France (V.M., P.J., M.H., M.H.); and Max Delbrück Center for Molecular Medicine, Berlin, Germany (S.G.).
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Wang K, Lee P, Mirams GR, Sarathchandra P, Borg TK, Gavaghan DJ, Kohl P, Bollensdorff C. Cardiac tissue slices: preparation, handling, and successful optical mapping. Am J Physiol Heart Circ Physiol 2015; 308:H1112-25. [PMID: 25595366 PMCID: PMC4551126 DOI: 10.1152/ajpheart.00556.2014] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 01/14/2015] [Indexed: 01/28/2023]
Abstract
Cardiac tissue slices are becoming increasingly popular as a model system for cardiac electrophysiology and pharmacology research and development. Here, we describe in detail the preparation, handling, and optical mapping of transmembrane potential and intracellular free calcium concentration transients (CaT) in ventricular tissue slices from guinea pigs and rabbits. Slices cut in the epicardium-tangential plane contained well-aligned in-slice myocardial cell strands (“fibers”) in subepicardial and midmyocardial sections. Cut with a high-precision slow-advancing microtome at a thickness of 350 to 400 μm, tissue slices preserved essential action potential (AP) properties of the precutting Langendorff-perfused heart. We identified the need for a postcutting recovery period of 36 min (guinea pig) and 63 min (rabbit) to reach 97.5% of final steady-state values for AP duration (APD) (identified by exponential fitting). There was no significant difference between the postcutting recovery dynamics in slices obtained using 2,3-butanedione 2-monoxime or blebistatin as electromechanical uncouplers during the cutting process. A rapid increase in APD, seen after cutting, was caused by exposure to ice-cold solution during the slicing procedure, not by tissue injury, differences in uncouplers, or pH-buffers (bicarbonate; HEPES). To characterize intrinsic patterns of CaT, AP, and conduction, a combination of multipoint and field stimulation should be used to avoid misinterpretation based on source-sink effects. In summary, we describe in detail the preparation, mapping, and data analysis approaches for reproducible cardiac tissue slice-based investigations into AP and CaT dynamics.
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Affiliation(s)
- Ken Wang
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Peter Lee
- Department of Physics, University of Oxford, Clarendon Laboratory, Oxford, United Kingdom
| | - Gary R Mirams
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Padmini Sarathchandra
- Harefield Heart Science Centre, National Heart and Lung Institute, Imperial College London, Middlesex, United Kingdom
| | - Thomas K Borg
- Department of Regenerative Medicine and Cell Biology, University of South Carolina School of Medicine, Charleston, South Carolina; and
| | - David J Gavaghan
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Peter Kohl
- Department of Computer Science, University of Oxford, Oxford, United Kingdom; Harefield Heart Science Centre, National Heart and Lung Institute, Imperial College London, Middlesex, United Kingdom
| | - Christian Bollensdorff
- Harefield Heart Science Centre, National Heart and Lung Institute, Imperial College London, Middlesex, United Kingdom; Qatar Cardiovascular Research Center, Qatar Foundation, Doha, Qatar
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80
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Fisher JAN, Salzberg BM. Two-Photon Excitation of Fluorescent Voltage-Sensitive Dyes: Monitoring Membrane Potential in the Infrared. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 859:427-53. [PMID: 26238063 DOI: 10.1007/978-3-319-17641-3_17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Functional imaging microscopy based on voltage-sensitive dyes (VSDs) has proven effective for revealing spatio-temporal patterns of activity in vivo and in vitro. Microscopy based on two-photon excitation of fluorescent VSDs offers the possibility of recording sub-millisecond membrane potential changes on micron length scales in cells that lie upwards of one millimeter below the brain's surface. Here we describe progress in monitoring membrane voltage using two-photon excitation (TPE) of VSD fluorescence, and detail an application of this emerging technology in which action potentials were recorded in single trials from individual mammalian nerve terminals in situ. Prospects for, and limitations of this method are reviewed.
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81
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Loew LM. Design and Use of Organic Voltage Sensitive Dyes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 859:27-53. [PMID: 26238048 DOI: 10.1007/978-3-319-17641-3_2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The chemistry and the physics of voltage sensitive dyes (VSDs) should be understood and appreciated as a prerequisite for their optimal application to problems in neuroscience cardiology. This chapter provides a basic understanding of the properties of the large variety of available organic VSDs. The mechanisms by which the dyes respond to voltage guides the best set up of the optics for recording or imaging electrophysiological activity. The physical and chemical properties of the dyes can be tuned to optimize delivery to and staining of the cells in different experimental preparations. The aim of this chapter is to arm the experimentalists who use the dyes with enough information and data to be able to intelligently choose the best dye for their specific requirements.
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Affiliation(s)
- Leslie M Loew
- Department of Cell Biology, R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT, 06030-6406, USA,
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82
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Walton RD, Bernus O. Towards Depth-Resolved Optical Imaging of Cardiac Electrical Activity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 859:405-23. [DOI: 10.1007/978-3-319-17641-3_16] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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83
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Klimas A, Entcheva E. Toward microendoscopy-inspired cardiac optogenetics in vivo: technical overview and perspective. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:080701. [PMID: 25117076 PMCID: PMC4161000 DOI: 10.1117/1.jbo.19.8.080701] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 07/17/2014] [Indexed: 05/13/2023]
Abstract
The ability to perform precise, spatially localized actuation and measurements of electrical activity in the heart is crucial in understanding cardiac electrophysiology and devising new therapeutic solutions for control of cardiac arrhythmias. Current cardiac imaging techniques (i.e. optical mapping) employ voltage- or calcium-sensitive fluorescent dyes to visualize the electrical signal propagation through cardiac syncytium in vitro or in situ with very high-spatiotemporal resolution. The extension of optogenetics into the cardiac field, where cardiac tissue is genetically altered to express light-sensitive ion channels allowing electrical activity to be elicited or suppressed in a precise cell-specific way, has opened the possibility for all-optical interrogation of cardiac electrophysiology. In vivo application of cardiac optogenetics faces multiple challenges and necessitates suitable optical systems employing fiber optics to actuate and sense electrical signals. In this technical perspective, we present a compendium of clinically relevant access routes to different parts of the cardiac electrical conduction system based on currently employed catheter imaging systems and determine the quantitative size constraints for endoscopic cardiac optogenetics. We discuss the relevant technical advancements in microendoscopy, cardiac imaging, and optogenetics and outline the strategies for combining them to create a portable, miniaturized fiber-based system for all-optical interrogation of cardiac electrophysiology in vivo.
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Affiliation(s)
- Aleksandra Klimas
- Stony Brook University, Department of Biomedical Engineering, Stony Brook, New York 11794, United States
| | - Emilia Entcheva
- Stony Brook University, Department of Biomedical Engineering, Stony Brook, New York 11794, United States
- Stony Brook University, Department of Physiology and Biophysics, Stony Brook, New York 11794, United States
- Stony Brook University, Institute for Molecular Cardiology, Stony Brook, New York 11794, United States
- Address all correspondence to: Emilia Entcheva, E-mail:
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84
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Abstract
In the past decade, optical mapping provided crucial mechanistic insight into electromechanical function and the mechanism of ventricular fibrillation. Therefore, to date, optical mapping dominates experimental cardiac electrophysiology. The first cardiac measurements involving optics were done in the early 1900s using the fast cinematograph that later evolved into methods for high-resolution activation and repolarization mapping and stimulation of specific cardiac cell types. The field of "optocardiography," therefore, emerged as the use of light for recording or interfering with cardiac physiology. In this review, we discuss how optocardiography developed into the dominant research technique in experimental cardiology. Furthermore, we envision how optocardiographic methods can be used in clinical cardiology.
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85
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Glukhov AV, Hage LT, Hansen BJ, Pedraza-Toscano A, Vargas-Pinto P, Hamlin RL, Weiss R, Carnes CA, Billman GE, Fedorov VV. Sinoatrial node reentry in a canine chronic left ventricular infarct model: role of intranodal fibrosis and heterogeneity of refractoriness. Circ Arrhythm Electrophysiol 2013; 6:984-94. [PMID: 23960214 DOI: 10.1161/circep.113.000404] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Reentrant arrhythmias involving the sinoatrial node (SAN), namely SAN reentry, remain one of the most intriguing enigmas of cardiac electrophysiology. The goal of the present study was to elucidate the mechanism of SAN micro-reentry in canine hearts with post-myocardial infarction (MI) structural remodeling. METHODS AND RESULTS In vivo, Holter monitoring revealed ventricular arrhythmias and SAN dysfunctions in post-left ventricular MI (6-15 weeks) dogs (n=5) compared with control dogs (n=4). In vitro, high-resolution near-infrared optical mapping of intramural SAN activation was performed in coronary perfused atrial preparations from MI (n=5) and controls (n=4). Both SAN macro- (slow-fast; 16-28 mm) and micro-reentry (1-3 mm) were observed in 60% of the MI preparations during moderate autonomic stimulation (acetylcholine [0.1 µmol/L] or isoproterenol [0.01-0.1 µmol/L]) after termination of atrial tachypacing (5-8 Hz), a finding not seen in controls. The autonomic stimulation induced heterogeneous changes in the SAN refractoriness; thus, competing atrial or SAN pacemaker waves could produce unidirectional blocks and initiate intranodal micro-reentry. The micro-reentry pivot waves were anchored to the longitudinal block region and produced both tachycardia and paradoxical bradycardia (due to exit block), despite an atrial ECG morphology identical to regular sinus rhythm. Intranodal longitudinal conduction blocks coincided with interstitial fibrosis strands that were exaggerated in the MI SAN pacemaker complex (fibrosis density: 37±7% MI versus 23±6% control; P<0.001). CONCLUSIONS Both tachy- and brady-arrhythmias can result from SAN micro-reentry. Postinfarction remodeling, including increased intranodal fibrosis and heterogeneity of refractoriness, provides substrates for SAN reentry.
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Affiliation(s)
- Alexey V Glukhov
- Department of Physiology and Cell Biology, College of Veterinary Medicine, Division of Cardiovascular Medicine, and College of Pharmacy, College of Medicine, Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
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86
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Park K, Deutsch Z, Li JJ, Oron D, Weiss S. Single molecule quantum-confined Stark effect measurements of semiconductor nanoparticles at room temperature. ACS NANO 2012; 6:10013-23. [PMID: 23075136 PMCID: PMC3507316 DOI: 10.1021/nn303719m] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 10/17/2012] [Indexed: 05/20/2023]
Abstract
We measured the quantum-confined Stark effect (QCSE) of several types of fluorescent colloidal semiconductor quantum dots and nanorods at the single molecule level at room temperature. These measurements demonstrate the possible utility of these nanoparticles for local electric field (voltage) sensing on the nanoscale. Here we show that charge separation across one (or more) heterostructure interface(s) with type-II band alignment (and the associated induced dipole) is crucial for an enhanced QCSE. To further gain insight into the experimental results, we numerically solved the Schrödinger and Poisson equations under self-consistent field approximation, including dielectric inhomogeneities. Both calculations and experiments suggest that the degree of initial charge separation (and the associated exciton binding energy) determines the magnitude of the QCSE in these structures.
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Affiliation(s)
- KyoungWon Park
- Electrical Engineering Department, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, California 90095, United States
| | - Zvicka Deutsch
- Department of Physics, The Weizmann Institute, Rehovot 76100, Israel
| | - J. Jack Li
- Department of Chemistry & Biochemistry, Department of Physiology, and California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
| | - Dan Oron
- Department of Physics, The Weizmann Institute, Rehovot 76100, Israel
| | - Shimon Weiss
- Department of Chemistry & Biochemistry, Department of Physiology, and California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
- Address correspondence to
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87
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Abstract
Optical recording of membrane potential permits spatially resolved measurement of electrical activity in subcellular regions of single cells, which would be inaccessible to electrodes, and imaging of spatiotemporal patterns of action potential propagation in excitable tissues, such as the brain or heart. However, the available voltage-sensitive dyes (VSDs) are not always spectrally compatible with newly available optical technologies for sensing or manipulating the physiological state of a system. Here, we describe a series of 19 fluorinated VSDs based on the hemicyanine class of chromophores. Strategic placement of the fluorine atoms on the chromophores can result in either blue or red shifts in the absorbance and emission spectra. The range of one-photon excitation wavelengths afforded by these new VSDs spans 440-670 nm; the two-photon excitation range is 900-1,340 nm. The emission of each VSD is shifted by at least 100 nm to the red of its one-photon excitation spectrum. The set of VSDs, thus, affords an extended toolkit for optical recording to match a broad range of experimental requirements. We show the sensitivity to voltage and the photostability of the new VSDs in a series of experimental preparations ranging in scale from single dendritic spines to whole heart. Among the advances shown in these applications are simultaneous recording of voltage and calcium in single dendritic spines and optical electrophysiology recordings using two-photon excitation above 1,100 nm.
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88
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Cardiac electrophysiological imaging systems scalable for high-throughput drug testing. Pflugers Arch 2012; 464:645-56. [PMID: 23053475 PMCID: PMC3513599 DOI: 10.1007/s00424-012-1149-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 08/22/2012] [Accepted: 08/24/2012] [Indexed: 12/02/2022]
Abstract
Multi-parametric electrophysiological measurements using optical methods have become a highly valued standard in cardiac research. Most published optical mapping systems are expensive and complex. Although some applications demand high-cost components and complex designs, many can be tackled with simpler solutions. Here, we describe (1) a camera-based voltage and calcium imaging system using a single ‘economy’ electron-multiplying charge-coupled device camera and demonstrate the possibility of using a consumer camera for imaging calcium transients of the heart, and (2) a photodiode-based voltage and calcium high temporal resolution measurement system using single-element photodiodes and an optical fibre. High-throughput drug testing represents an application where system scalability is particularly attractive. Therefore, we tested our systems on tissue exposed to a well-characterized and clinically relevant calcium channel blocker, nifedipine, which has been used to treat angina and hypertension. As experimental models, we used the Langendorff-perfused whole-heart and thin ventricular tissue slices, a preparation gaining renewed interest by the cardiac research community. Using our simplified systems, we were able to monitor simultaneously the marked changes in the voltage and calcium transients that are responsible for the negative inotropic effect of the compound.
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89
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Atienza F, Martins RP, Jalife J. Translational research in atrial fibrillation: a quest for mechanistically based diagnosis and therapy. Circ Arrhythm Electrophysiol 2012; 5:1207-15. [PMID: 23022707 DOI: 10.1161/circep.111.970335] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Felipe Atienza
- Hospital General Universitario Gregorio Marañón, Madrid, Spain
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90
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Lou Q, Glukhov AV, Hansen B, Hage L, Vargas-Pinto P, Billman GE, Carnes CA, Fedorov VV. Tachy-brady arrhythmias: the critical role of adenosine-induced sinoatrial conduction block in post-tachycardia pauses. Heart Rhythm 2012; 10:110-8. [PMID: 22985657 DOI: 10.1016/j.hrthm.2012.09.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Indexed: 11/30/2022]
Abstract
BACKGROUND In patients with sinoatrial nodal (SAN) dysfunction, atrial pauses lasting several seconds may follow rapid atrial pacing or paroxysmal tachycardia (tachy-brady arrhythmias). Clinical studies suggest that adenosine may play an important role in SAN dysfunction, but the mechanism remains unclear. OBJECTIVE To define the mechanism of SAN dysfunction induced by the combination of adenosine and tachycardia. METHODS We studied the mechanism of SAN dysfunction produced by a combination of adenosine and rapid atrial pacing in isolated coronary-perfused canine atrial preparations by using high-resolution optical mapping (n = 9). Sinus cycle length and sinoatrial conduction time (SACT) were measured during adenosine (1-100 μM) and DPCPX (1 μM; A1 receptor antagonist; n = 7) perfusion. Sinoatrial node recovery time was measured after 1 minute of "slow" pacing (3.3 Hz) or tachypacing (7-9 Hz). RESULTS Adenosine significantly increased sinus cycle length (477 ± 62 ms vs 778 ± 114 ms; P<.01) and SACT during sinus rhythm (41 ± 11 ms vs 86 ± 16 ms; P<.01) in a dose-dependent manner. Adenosine dramatically affected SACT of the first SAN beat after tachypacing (41 ± 5 ms vs 221 ± 98 ms; P<.01). Moreover, at high concentrations of adenosine (10-100 μM), termination of tachypacing or atrial flutter/fibrillation produced atrial pauses of 4.2 ± 3.4 seconds (n = 5) owing to conduction block between the SAN and the atria, despite a stable SAN intrinsic rate. Conduction block was preferentially related to depressed excitability in SAN conduction pathways. Adenosine-induced changes were reversible on washout or DPCPX treatment. CONCLUSIONS These data directly demonstrate that adenosine contributes to post-tachycardia atrial pauses through SAN exit block rather than slowed pacemaker automaticity. Thus, these data suggest an important modulatory role of adenosine in tachy-brady syndrome.
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Affiliation(s)
- Qing Lou
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio 43210-1218, USA
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91
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Kanaporis G, Martišienė I, Jurevičius J, Vosyliūtė R, Navalinskas A, Treinys R, Matiukas A, Pertsov AM. Optical mapping at increased illumination intensities. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:96007-1. [PMID: 23085908 PMCID: PMC3602814 DOI: 10.1117/1.jbo.17.9.096007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 07/19/2012] [Accepted: 08/14/2012] [Indexed: 05/25/2023]
Abstract
Voltage-sensitive fluorescent dyes have become a major tool in cardiac and neuro-electrophysiology. Achieving high signal-to-noise ratios requires increased illumination intensities, which may cause photobleaching and phototoxicity. The optimal range of illumination intensities varies for different dyes and must be evaluated individually. We evaluate two dyes: di-4-ANBDQBS (excitation 660 nm) and di-4-ANEPPS (excitation 532 nm) in the guinea pig heart. The light intensity varies from 0.1 to 5 mW/mm2, with the upper limit at 5 to 10 times above values reported in the literature. The duration of illumination was 60 s, which in guinea pigs corresponds to 300 beats at a normal heart rate. Within the identified duration and intensity range, neither dye shows significant photobleaching or detectable phototoxic effects. However, light absorption at higher intensities causes noticeable tissue heating, which affects the electrophysiological parameters. The most pronounced effect is a shortening of the action potential duration, which, in the case of 532-nm excitation, can reach ∼30%. At 660-nm excitation, the effect is ∼10%. These findings may have important implications for the design of optical mapping protocols in biomedical applications.
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Affiliation(s)
- Giedrius Kanaporis
- Lithuanian University of Health Sciences, Institute of Cardiology, Laboratory of Membrane Biophysics, 17 Sukilėlių pr, Kaunas 50161, Lithuania
| | - Irma Martišienė
- Lithuanian University of Health Sciences, Institute of Cardiology, Laboratory of Membrane Biophysics, 17 Sukilėlių pr, Kaunas 50161, Lithuania
| | - Jonas Jurevičius
- Lithuanian University of Health Sciences, Institute of Cardiology, Laboratory of Membrane Biophysics, 17 Sukilėlių pr, Kaunas 50161, Lithuania
| | - Rūta Vosyliūtė
- Lithuanian University of Health Sciences, Institute of Cardiology, Laboratory of Membrane Biophysics, 17 Sukilėlių pr, Kaunas 50161, Lithuania
| | - Antanas Navalinskas
- Lithuanian University of Health Sciences, Institute of Cardiology, Laboratory of Membrane Biophysics, 17 Sukilėlių pr, Kaunas 50161, Lithuania
| | - Rimantas Treinys
- Lithuanian University of Health Sciences, Institute of Cardiology, Laboratory of Membrane Biophysics, 17 Sukilėlių pr, Kaunas 50161, Lithuania
| | - Arvydas Matiukas
- SUNY Upstate Medical University, Department of Pharmacology, 750 East Adams Street, Syracuse, New York 13210
| | - Arkady M. Pertsov
- Lithuanian University of Health Sciences, Institute of Cardiology, Laboratory of Membrane Biophysics, 17 Sukilėlių pr, Kaunas 50161, Lithuania
- SUNY Upstate Medical University, Department of Pharmacology, 750 East Adams Street, Syracuse, New York 13210
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92
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Lee P, Yan P, Ewart P, Kohl P, Loew LM, Bollensdorff C. Simultaneous measurement and modulation of multiple physiological parameters in the isolated heart using optical techniques. Pflugers Arch 2012; 464:403-14. [PMID: 22886365 DOI: 10.1007/s00424-012-1135-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 06/23/2012] [Accepted: 06/26/2012] [Indexed: 10/28/2022]
Abstract
Whole-heart multi-parametric optical mapping has provided valuable insight into the interplay of electrophysiological parameters, and this technology will continue to thrive as dyes are improved and technical solutions for imaging become simpler and cheaper. Here, we show the advantage of using improved 2nd-generation voltage dyes, provide a simple solution to panoramic multi-parametric mapping, and illustrate the application of flash photolysis of caged compounds for studies in the whole heart. For proof of principle, we used the isolated rat whole-heart model. After characterising the blue and green isosbestic points of di-4-ANBDQBS and di-4-ANBDQPQ, respectively, two voltage and calcium mapping systems are described. With two newly custom-made multi-band optical filters, (1) di-4-ANBDQBS and fluo-4 and (2) di-4-ANBDQPQ and rhod-2 mapping are demonstrated. Furthermore, we demonstrate three-parameter mapping using di-4-ANBDQPQ, rhod-2 and NADH. Using off-the-shelf optics and the di-4-ANBDQPQ and rhod-2 combination, we demonstrate panoramic multi-parametric mapping, affording a 360° spatiotemporal record of activity. Finally, local optical perturbation of calcium dynamics in the whole heart is demonstrated using the caged compound, o-nitrophenyl ethylene glycol tetraacetic acid (NP-EGTA), with an ultraviolet light-emitting diode (LED). Calcium maps (heart loaded with di-4-ANBDQPQ and rhod-2) demonstrate successful NP-EGTA loading and local flash photolysis. All imaging systems were built using only a single camera. In conclusion, using novel 2nd-generation voltage dyes, we developed scalable techniques for multi-parametric optical mapping of the whole heart from one point of view and panoramically. In addition to these parameter imaging approaches, we show that it is possible to use caged compounds and ultraviolet LEDs to locally perturb electrophysiological parameters in the whole heart.
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Affiliation(s)
- Peter Lee
- Department of Physics, University of Oxford, Oxford, UK
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93
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Lee P, Taghavi F, Yan P, Ewart P, Ashley EA, Loew LM, Kohl P, Bollensdorff C, Woods CE. In situ optical mapping of voltage and calcium in the heart. PLoS One 2012; 7:e42562. [PMID: 22876327 PMCID: PMC3411684 DOI: 10.1371/journal.pone.0042562] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 07/09/2012] [Indexed: 11/30/2022] Open
Abstract
Electroanatomic mapping the interrelation of intracardiac electrical activation with anatomic locations has become an important tool for clinical assessment of complex arrhythmias. Optical mapping of cardiac electrophysiology combines high spatiotemporal resolution of anatomy and physiological function with fast and simultaneous data acquisition. If applied to the clinical setting, this could improve both diagnostic potential and therapeutic efficacy of clinical arrhythmia interventions. The aim of this study was to explore this utility in vivo using a rat model. To this aim, we present a single-camera imaging and multiple light-emitting-diode illumination system that reduces economic and technical implementation hurdles to cardiac optical mapping. Combined with a red-shifted calcium dye and a new near-infrared voltage-sensitive dye, both suitable for use in blood-perfused tissue, we demonstrate the feasibility of in vivo multi-parametric imaging of the mammalian heart. Our approach combines recording of electrophysiologically-relevant parameters with observation of structural substrates and is adaptable, in principle, to trans-catheter percutaneous approaches.
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Affiliation(s)
- Peter Lee
- Department of Physics, University of Oxford, Oxford, United Kingdom
| | - Fouad Taghavi
- Division of Cardiothoracic Surgery, Papworth Hosptial, Cambridge, United Kingdom
| | - Ping Yan
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, Connecticut, United States of America
| | - Paul Ewart
- Department of Physics, University of Oxford, Oxford, United Kingdom
| | - Euan A. Ashley
- Department of Medicine, Stanford University, Stanford, California, United States of America
| | - Leslie M. Loew
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, Connecticut, United States of America
| | - Peter Kohl
- National Heart and Lung Institute, Imperial College, London, United Kingdom
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Christian Bollensdorff
- National Heart and Lung Institute, Imperial College, London, United Kingdom
- * E-mail: (CB); (CEW)
| | - Christopher E. Woods
- Department of Medicine, Stanford University, Stanford, California, United States of America
- * E-mail: (CB); (CEW)
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94
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Liao R, Podesser BK, Lim CC. The continuing evolution of the Langendorff and ejecting murine heart: new advances in cardiac phenotyping. Am J Physiol Heart Circ Physiol 2012; 303:H156-67. [PMID: 22636675 DOI: 10.1152/ajpheart.00333.2012] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The isolated retrograde-perfused Langendorff heart and the isolated ejecting heart have, over many decades, resulted in fundamental discoveries that form the underpinnings of our current understanding of the biology and physiology of the heart. These two experimental methodologies have proven invaluable in studying pharmacological effects on myocardial function, metabolism, and vascular reactivity and in the investigation of clinically relevant disease states such as ischemia-reperfusion injury, diabetes, obesity, and heart failure. With the advent of the genomics era, the isolated mouse heart preparation has gained prominence as an ex vivo research tool for investigators studying the impact of gene modification in the intact heart. This review summarizes the historical development of the isolated heart and provides a practical guide for the establishment of the Langendorff and ejecting heart preparations with a particular emphasis on the murine heart. In addition, current applications and novel methods of recording cardiovascular parameters in the isolated heart preparation will be discussed. With continued advances in methodological recordings, the isolated mouse heart preparation will remain physiologically relevant for the foreseeable future, serving as an integral bridge between in vitro assays and in vivo approaches.
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Affiliation(s)
- Ronglih Liao
- Cardiac Muscle Research Laboratory, Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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95
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Abstract
Cardiac optical mapping has proven to be a powerful technology for studying cardiovascular function and disease. The development and scientific impact of this methodology are well-documented. Because of its relevance in cardiac research, this imaging technology advances at a rapid pace. Here, we review technological and scientific developments during the past several years and look toward the future. First, we explore key components of a modern optical mapping set-up, focusing on: (1) new camera technologies; (2) powerful light-emitting-diodes (from ultraviolet to red) for illumination; (3) improved optical filter technology; (4) new synthetic and optogenetic fluorescent probes; (5) optical mapping with motion and contraction; (6) new multiparametric optical mapping techniques; and (7) photon scattering effects in thick tissue preparations. We then look at recent optical mapping studies in single cells, cardiomyocyte monolayers, atria, and whole hearts. Finally, we briefly look into the possible future roles of optical mapping in the development of regenerative cardiac research, cardiac cell therapies, and molecular genetic advances.
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Affiliation(s)
- Todd J Herron
- Department of Internal Medicine, Cardiovascular Research Center, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI 48109-2800, USA
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96
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Walton RD, Smith RM, Mitrea BG, White E, Bernus O, Pertsov AM. Extracting surface activation time from the optically recorded action potential in three-dimensional myocardium. Biophys J 2012; 102:30-8. [PMID: 22225795 DOI: 10.1016/j.bpj.2011.10.036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 10/15/2011] [Accepted: 10/18/2011] [Indexed: 10/14/2022] Open
Abstract
Optical mapping has become an indispensible tool for studying cardiac electrical activity. However, due to the three-dimensional nature of the optical signal, the optical upstroke is significantly longer than the electrical upstroke. This raises the issue of how to accurately determine the activation time on the epicardial surface. The purpose of this study was to establish a link between the optical upstroke and exact surface activation time using computer simulations, with subsequent validation by a combination of microelectrode recordings and optical mapping experiments. To simulate wave propagation and associated optical signals, we used a hybrid electro-optical model. We found that the time of the surface electrical activation (t(E)) within the accuracy of our simulations coincided with the maximal slope of the optical upstroke (t(F)*) for a broad range of optical attenuation lengths. This was not the case when the activation time was determined at 50% amplitude (t(F50)) of the optical upstroke. The validation experiments were conducted in isolated Langendorff-perfused rat hearts and coronary-perfused pig left ventricles stained with either di-4-ANEPPS or the near-infrared dye di-4-ANBDQBS. We found that t(F)* was a more accurate measure of t(E) than was t(F50) in all experimental settings tested (P = 0.0002). Using t(F)* instead of t(F50) produced the most significant improvement in measurements of the conduction anisotropy and the transmural conduction time in pig ventricles.
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Affiliation(s)
- Richard D Walton
- Institute of Membrane and Systems Biology, Faculty of Biological Sciences, Multidisciplinary Cardiovascular Research Center, University of Leeds, Leeds, United Kingdom
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97
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Affiliation(s)
- Stanley Nattel
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada
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98
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Kaestner L, Lipp P. Screening action potentials: the power of light. Front Pharmacol 2011; 2:42. [PMID: 21847381 PMCID: PMC3147179 DOI: 10.3389/fphar.2011.00042] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Accepted: 07/12/2011] [Indexed: 11/13/2022] Open
Abstract
Action potentials reflect the concerted activity of all electrogenic constituents in the plasma membrane during the excitation of a cell. Therefore, the action potential is an integrated read out and a promising parameter to detect electrophysiological failures or modifications thereof in diagnosis as well as in drug screens. Cellular action potentials can be recorded by optical approaches. To fulfill the pre-requirements to scale up for, e.g., pharmacological screens the following preparatory work has to be provided: (i) model cells under investigation need to represent target cells in the best possible manner; (ii) optical sensors that can be either small molecule dyes or genetically encoded potential probes need to provide a reliable read out with minimal interaction with the naive behavior of the cells and (iii) devices need to be capable to stimulate the cells, read out the signals with the appropriate speed as well as provide the capacity for a sufficient throughput. Here we discuss several scenarios for all three categories in the field of cardiac physiology and pharmacology and provide a perspective to use the power of light in screening cardiac action potentials.
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Affiliation(s)
- Lars Kaestner
- Institute for Molecular Cell Biology, School of Medicine, Saarland University Homburg/Saar, Germany
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99
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Fedorov VV, Ambrosi CM, Kostecki G, Hucker WJ, Glukhov AV, Wuskell JP, Loew LM, Moazami N, Efimov IR. Anatomic localization and autonomic modulation of atrioventricular junctional rhythm in failing human hearts. Circ Arrhythm Electrophysiol 2011; 4:515-25. [PMID: 21646375 DOI: 10.1161/circep.111.962258] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The structure-function relationship in the atrioventricular junction (AVJ) of various animal species has been investigated in detail; however, less is known about the human AVJ. In this study, we performed high-resolution optical mapping of the human AVJ (n = 6) to define its pacemaker properties and response to autonomic stimulation. METHODS AND RESULTS Isolated, coronary-perfused AVJ preparations from failing human hearts (n = 6, 53 ± 6 years) were optically mapped using the near-infrared, voltage-sensitive dye, di-4-ANBDQBS, with isoproterenol (1 μmol/L) and acetylcholine (1 μmol/L). An algorithm detecting multiple components of optical action potentials was used to reconstruct multilayered intramural AVJ activation and to identify specialized slow and fast conduction pathways (SP and FP). The anatomic origin and propagation of pacemaker activity was verified by histology. Spontaneous AVJ rhythms of 29 ± 11 bpm (n = 6) originated in the nodal-His region (n = 3) and/or the proximal His bundle (n = 4). Isoproterenol accelerated the AVJ rhythm to 69 ± 12 bpm (n = 5); shifted the leading pacemaker to the transitional cell regions near the FP and SP (n = 4) and/or coronary sinus (n = 2); and triggered reentrant arrhythmias (n = 2). Acetylcholine (n = 4) decreased the AVJ rhythm to 18 ± 4 bpm; slowed FP/SP conduction leading to block between the AVJ and atrium; and shifted the pacemaker to either the transitional cell region or the nodal-His region (bifocal activation). CONCLUSIONS We have demonstrated that the AVJ pacemaker in failing human hearts is located in the nodal-His region or His bundle regions and can be modified with autonomic stimulation. Moreover, we found that both the FP and SP are involved in anterograde and retrograde conduction.
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Affiliation(s)
- Vadim V Fedorov
- Department of Biomedical Engineering, Washington University in St Louis, MO, USA
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100
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Licari FG, Shkoukani M, Kaltenbach JA. Stimulus-dependent changes in optical responses of the dorsal cochlear nucleus using voltage-sensitive dye. J Neurophysiol 2011; 106:421-36. [PMID: 21543759 DOI: 10.1152/jn.00982.2010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Optical imaging with voltage-sensitive dye was used to examine the spatiotemporal dynamics of stimulus-driven activity on the surface of the dorsal cochlear nucleus (DCN). Stimulation with tones at low to moderate levels produced localized regions of activation that were most commonly elongated rostrocaudally. The size of these activation areas expanded with increases in sound level, while their centers shifted from the lateral direction to the medial direction with increases in stimulus frequency. In contrast to the tonotopic patterns of activation evoked by tones, electrical stimulation of the DCN surface resulted in bands of activation that were elongated along the medial-lateral axis; response latencies increased with distance along these bands from the point of stimulation. Shifting the site of electrical stimulation from the rostral direction to the caudal direction induced corresponding shifts in the rostrocaudal location of the activation band; moving the electrode tip to subsurface depths resulted in loss of the elongated band. Transecting the DCN along the rostrocaudal axis midway between its medial and lateral extremities blocked propagation of the response to the half of the DCN distal to but not proximal to the stimulating electrode. The results suggest that the two modes of stimulation activated two distinct populations of neurons, one involving primarily tonotopically organized cells and the other crossing these tonotopic zones and likely representing the activation of parallel fibers. These results reveal a number of new features in the spatial patterns of tone-elicited activation that are not readily predicted by responses recorded electrophysiologically.
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Affiliation(s)
- F G Licari
- Department of Neurosciences and The Head and Neck Institute, The Cleveland Clinic, Cleveland, Ohio 44195, USA
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