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Ma J, Sun R, Xia K, Xia Q, Liu Y, Zhang X. Design and Application of Fluorescent Probes to Detect Cellular Physical Microenvironments. Chem Rev 2024; 124:1738-1861. [PMID: 38354333 DOI: 10.1021/acs.chemrev.3c00573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
The microenvironment is indispensable for functionality of various biomacromolecules, subcellular compartments, living cells, and organisms. In particular, physical properties within the biological microenvironment could exert profound effects on both the cellular physiology and pathology, with parameters including the polarity, viscosity, pH, and other relevant factors. There is a significant demand to directly visualize and quantitatively measure the fluctuation in the cellular microenvironment with spatiotemporal resolution. To satisfy this need, analytical methods based on fluorescence probes offer great opportunities due to the facile, sensitive, and dynamic detection that these molecules could enable in varying biological settings from in vitro samples to live animal models. Herein, we focus on various types of small molecule fluorescent probes for the detection and measurement of physical parameters of the microenvironment, including pH, polarity, viscosity, mechanical force, temperature, and electron potential. For each parameter, we primarily describe the chemical mechanisms underlying how physical properties are correlated with changes of various fluorescent signals. This review provides both an overview and a perspective for the development of small molecule fluorescent probes to visualize the dynamic changes in the cellular environment, to expand the knowledge for biological process, and to enrich diagnostic tools for human diseases.
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Affiliation(s)
- Junbao Ma
- Department of Chemistry and Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou 310030, Zhejiang Province, China
- Westlake Laboratory of Life Sciences and Biomedicine, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou 310030, Zhejiang Province, China
| | - Rui Sun
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
- University of the Chinese Academy of Sciences, 19 A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Kaifu Xia
- Department of Chemistry and Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou 310030, Zhejiang Province, China
- Westlake Laboratory of Life Sciences and Biomedicine, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou 310030, Zhejiang Province, China
| | - Qiuxuan Xia
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
- University of the Chinese Academy of Sciences, 19 A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Yu Liu
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
- State Key Laboratory of Medical Proteomics, National Chromatographic R. & A. Center, Chinese Academy of Sciences Dalian Liaoning 116023, China
| | - Xin Zhang
- Department of Chemistry and Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou 310030, Zhejiang Province, China
- Westlake Laboratory of Life Sciences and Biomedicine, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
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Xiang Y, Shi K, Li Y, Xue J, Tong Z, Li H, Li Z, Teng C, Fang J, Hu N. Active Micro-Nano-Collaborative Bioelectronic Device for Advanced Electrophysiological Recording. NANO-MICRO LETTERS 2024; 16:132. [PMID: 38411852 PMCID: PMC10899154 DOI: 10.1007/s40820-024-01336-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 12/28/2023] [Indexed: 02/28/2024]
Abstract
The development of precise and sensitive electrophysiological recording platforms holds the utmost importance for research in the fields of cardiology and neuroscience. In recent years, active micro/nano-bioelectronic devices have undergone significant advancements, thereby facilitating the study of electrophysiology. The distinctive configuration and exceptional functionality of these active micro-nano-collaborative bioelectronic devices offer the potential for the recording of high-fidelity action potential signals on a large scale. In this paper, we review three-dimensional active nano-transistors and planar active micro-transistors in terms of their applications in electro-excitable cells, focusing on the evaluation of the effects of active micro/nano-bioelectronic devices on electrophysiological signals. Looking forward to the possibilities, challenges, and wide prospects of active micro-nano-devices, we expect to advance their progress to satisfy the demands of theoretical investigations and medical implementations within the domains of cardiology and neuroscience research.
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Affiliation(s)
- Yuting Xiang
- Department of Chemistry, Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310058, People's Republic of China
- Department of Obstetrics and Gynecology, The Tenth Affiliated Hospital, Southern Medical University, Dongguan, 523059, People's Republic of China
- Dongguan Key Laboratory of Major Diseases in Obstetrics and Gynecology, Dongguan, 523059, People's Republic of China
| | - Keda Shi
- Department of Lung Transplantation and General Thoracic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, People's Republic of China
| | - Ying Li
- School of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, People's Republic of China
| | - Jiajin Xue
- General Surgery Department, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Children's Health, Hangzhou, 310052, People's Republic of China
| | - Zhicheng Tong
- Department of Orthopedics, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, 322005, People's Republic of China
| | - Huiming Li
- Department of Orthopedics, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, 322005, People's Republic of China
| | - Zhongjun Li
- Department of Obstetrics and Gynecology, The Tenth Affiliated Hospital, Southern Medical University, Dongguan, 523059, People's Republic of China.
- Dongguan Key Laboratory of Major Diseases in Obstetrics and Gynecology, Dongguan, 523059, People's Republic of China.
| | - Chong Teng
- Department of Orthopedics, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, 322005, People's Republic of China.
| | - Jiaru Fang
- School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510006, People's Republic of China.
| | - Ning Hu
- Department of Chemistry, Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310058, People's Republic of China.
- General Surgery Department, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Children's Health, Hangzhou, 310052, People's Republic of China.
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Baines O, Sha R, Kalla M, Holmes AP, Efimov IR, Pavlovic D, O’Shea C. Optical mapping and optogenetics in cardiac electrophysiology research and therapy: a state-of-the-art review. Europace 2024; 26:euae017. [PMID: 38227822 PMCID: PMC10847904 DOI: 10.1093/europace/euae017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 12/07/2023] [Accepted: 01/12/2024] [Indexed: 01/18/2024] Open
Abstract
State-of-the-art innovations in optical cardiac electrophysiology are significantly enhancing cardiac research. A potential leap into patient care is now on the horizon. Optical mapping, using fluorescent probes and high-speed cameras, offers detailed insights into cardiac activity and arrhythmias by analysing electrical signals, calcium dynamics, and metabolism. Optogenetics utilizes light-sensitive ion channels and pumps to realize contactless, cell-selective cardiac actuation for modelling arrhythmia, restoring sinus rhythm, and probing complex cell-cell interactions. The merging of optogenetics and optical mapping techniques for 'all-optical' electrophysiology marks a significant step forward. This combination allows for the contactless actuation and sensing of cardiac electrophysiology, offering unprecedented spatial-temporal resolution and control. Recent studies have performed all-optical imaging ex vivo and achieved reliable optogenetic pacing in vivo, narrowing the gap for clinical use. Progress in optical electrophysiology continues at pace. Advances in motion tracking methods are removing the necessity of motion uncoupling, a key limitation of optical mapping. Innovations in optoelectronics, including miniaturized, biocompatible illumination and circuitry, are enabling the creation of implantable cardiac pacemakers and defibrillators with optoelectrical closed-loop systems. Computational modelling and machine learning are emerging as pivotal tools in enhancing optical techniques, offering new avenues for analysing complex data and optimizing therapeutic strategies. However, key challenges remain including opsin delivery, real-time data processing, longevity, and chronic effects of optoelectronic devices. This review provides a comprehensive overview of recent advances in optical mapping and optogenetics and outlines the promising future of optics in reshaping cardiac electrophysiology and therapeutic strategies.
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Affiliation(s)
- Olivia Baines
- Institute of Cardiovascular Sciences, College of Medical and Dental Science, University of Birmingham, Edgbastion, Wolfson Drive, Birmingham B15 2TT, UK
| | - Rina Sha
- Institute of Cardiovascular Sciences, College of Medical and Dental Science, University of Birmingham, Edgbastion, Wolfson Drive, Birmingham B15 2TT, UK
| | - Manish Kalla
- Institute of Cardiovascular Sciences, College of Medical and Dental Science, University of Birmingham, Edgbastion, Wolfson Drive, Birmingham B15 2TT, UK
| | - Andrew P Holmes
- Institute of Cardiovascular Sciences, College of Medical and Dental Science, University of Birmingham, Edgbastion, Wolfson Drive, Birmingham B15 2TT, UK
| | - Igor R Efimov
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
- Department of Medicine, Division of Cardiology, Northwestern University, Evanston, IL, USA
| | - Davor Pavlovic
- Institute of Cardiovascular Sciences, College of Medical and Dental Science, University of Birmingham, Edgbastion, Wolfson Drive, Birmingham B15 2TT, UK
| | - Christopher O’Shea
- Institute of Cardiovascular Sciences, College of Medical and Dental Science, University of Birmingham, Edgbastion, Wolfson Drive, Birmingham B15 2TT, UK
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Iravanian S, Uzelac I, Shah AD, Toye MJ, Lloyd MS, Burke MA, Daneshmand MA, Attia TS, Vega JD, El-Chami MF, Merchant FM, Cherry EM, Bhatia NK, Fenton FH. Complex repolarization dynamics in ex vivo human ventricles are independent of the restitution properties. Europace 2023; 25:euad350. [PMID: 38006390 PMCID: PMC10751849 DOI: 10.1093/europace/euad350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 11/13/2023] [Indexed: 11/27/2023] Open
Abstract
AIMS The mechanisms of transition from regular rhythms to ventricular fibrillation (VF) are poorly understood. The concordant to discordant repolarization alternans pathway is extensively studied; however, despite its theoretical centrality, cannot guide ablation. We hypothesize that complex repolarization dynamics, i.e. oscillations in the repolarization phase of action potentials with periods over two of classic alternans, is a marker of electrically unstable substrate, and ablation of these areas has a stabilizing effect and may reduce the risk of VF. To prove the existence of higher-order periodicities in human hearts. METHODS AND RESULTS We performed optical mapping of explanted human hearts obtained from recipients of heart transplantation at the time of surgery. Signals recorded from the right ventricle endocardial surface were processed to detect global and local repolarization dynamics during rapid pacing. A statistically significant global 1:4 peak was seen in three of six hearts. Local (pixel-wise) analysis revealed the spatially heterogeneous distribution of Periods 4, 6, and 8, with the regional presence of periods greater than two in all the hearts. There was no significant correlation between the underlying restitution properties and the period of each pixel. CONCLUSION We present evidence of complex higher-order periodicities and the co-existence of such regions with stable non-chaotic areas in ex vivo human hearts. We infer that the oscillation of the calcium cycling machinery is the primary mechanism of higher-order dynamics. These higher-order regions may act as niduses of instability and may provide targets for substrate-based ablation of VF.
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Affiliation(s)
- Shahriar Iravanian
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Ilija Uzelac
- Georgia Institute of Technology, Department of Physics, 837 State St NW, Atlanta, GA 30332, USA
| | - Anand D Shah
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Mikael J Toye
- Georgia Institute of Technology, Department of Physics, 837 State St NW, Atlanta, GA 30332, USA
| | - Michael S Lloyd
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Michael A Burke
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Mani A Daneshmand
- Department of Surgery, Division of Cardiovascular Surgery, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Tamer S Attia
- Department of Surgery, Division of Cardiovascular Surgery, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - John David Vega
- Department of Surgery, Division of Cardiovascular Surgery, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Mikhael F El-Chami
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Faisal M Merchant
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Elizabeth M Cherry
- Georgia Institute of Technology, Department of Physics, 837 State St NW, Atlanta, GA 30332, USA
| | - Neal K Bhatia
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Flavio H Fenton
- Georgia Institute of Technology, Department of Physics, 837 State St NW, Atlanta, GA 30332, USA
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Zhang H, Patton HN, Wood GA, Yan P, Loew LM, Acker CD, Walcott GP, Rogers JM. Optical mapping of cardiac electromechanics in beating in vivo hearts. Biophys J 2023; 122:4207-4219. [PMID: 37775969 PMCID: PMC10645561 DOI: 10.1016/j.bpj.2023.09.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 08/31/2023] [Accepted: 09/26/2023] [Indexed: 10/01/2023] Open
Abstract
Optical mapping has been widely used in the study of cardiac electrophysiology in motion-arrested, ex vivo heart preparations. Recent developments in motion artifact mitigation techniques have made it possible to optically map beating ex vivo hearts, enabling the study of cardiac electromechanics using optical mapping. However, the ex vivo setting imposes limitations on optical mapping such as altered metabolic states, oversimplified mechanical loads, and the absence of neurohormonal regulation. In this study, we demonstrate optical electromechanical mapping in an in vivo heart preparation. Swine hearts were exposed via median sternotomy. Voltage-sensitive dye, either di-4-ANEQ(F)PTEA or di-5-ANEQ(F)PTEA, was injected into the left anterior descending artery. Fluorescence was excited by alternating green and amber light for excitation ratiometry. Cardiac motion during sinus and paced rhythm was tracked using a marker-based method. Motion tracking and excitation ratiometry successfully corrected most motion artifact in the membrane potential signal. Marker-based motion tracking also allowed simultaneous measurement of epicardial deformation. Reconstructed membrane potential and mechanical deformation measurements were validated using monophasic action potentials and sonomicrometry, respectively. Di-5-ANEQ(F)PTEA produced longer working time and higher signal/noise ratio than di-4-ANEQ(F)PTEA. In addition, we demonstrate potential applications of the new optical mapping system including electromechanical mapping during vagal nerve stimulation, fibrillation/defibrillation. and acute regional ischemia. In conclusion, although some technical limitations remain, optical mapping experiments that simultaneously image electrical and mechanical function can be conducted in beating, in vivo hearts.
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Affiliation(s)
- Hanyu Zhang
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Haley N Patton
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Garrett A Wood
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Ping Yan
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, Connecticut
| | - Leslie M Loew
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, Connecticut
| | - Corey D Acker
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, Connecticut
| | - Gregory P Walcott
- Department of Medicine, Division of Cardiovascular Disease, 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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Marchal GA, Biasci V, Yan P, Palandri C, Campione M, Cerbai E, Loew LM, Sacconi L. Recent advances and current limitations of available technology to optically manipulate and observe cardiac electrophysiology. Pflugers Arch 2023; 475:1357-1366. [PMID: 37770585 PMCID: PMC10567935 DOI: 10.1007/s00424-023-02858-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/28/2023] [Accepted: 09/06/2023] [Indexed: 09/30/2023]
Abstract
Optogenetics, utilising light-reactive proteins to manipulate tissue activity, are a relatively novel approach in the field of cardiac electrophysiology. We here provide an overview of light-activated transmembrane channels (optogenetic actuators) currently applied in strategies to modulate cardiac activity, as well as newly developed variants yet to be implemented in the heart. In addition, we touch upon genetically encoded indicators (optogenetic sensors) and fluorescent dyes to monitor tissue activity, including cardiac transmembrane potential and ion homeostasis. The combination of the two allows for all-optical approaches to monitor and manipulate the heart without any physical contact. However, spectral congestion poses a major obstacle, arising due to the overlap of excitation/activation and emission spectra of various optogenetic proteins and/or fluorescent dyes, resulting in optical crosstalk. Therefore, optogenetic proteins and fluorescent dyes should be carefully selected to avoid optical crosstalk and consequent disruptions in readouts and/or cellular activity. We here present a novel approach to simultaneously monitor transmembrane potential and cytosolic calcium, while also performing optogenetic manipulation. For this, we used the novel voltage-sensitive dye ElectroFluor 730p and the cytosolic calcium indicator X-Rhod-1 in mouse hearts expressing channelrhodopsin-2 (ChR2). By exploiting the isosbestic point of ElectroFluor 730p and avoiding the ChR2 activation spectrum, we here introduce a novel optical imaging and manipulation approach with minimal crosstalk. Future developments in both optogenetic proteins and fluorescent dyes will allow for additional and more optimised strategies, promising a bright future for all-optical approaches in the field of cardiac electrophysiology.
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Affiliation(s)
| | - Valentina Biasci
- European Laboratory for Non-Linear Spectroscopy-LENS, Sesto Fiorentino, Florence, Italy
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Ping Yan
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Chiara Palandri
- Department NeuroFarBa, University of Florence, Florence, Italy
| | - Marina Campione
- Institute of Neuroscience (IN-CNR) and Department of Biomedical Science, University of Padua, Padua, Italy
| | - Elisabetta Cerbai
- European Laboratory for Non-Linear Spectroscopy-LENS, Sesto Fiorentino, Florence, Italy
- Department NeuroFarBa, University of Florence, Florence, Italy
| | - Leslie M Loew
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Leonardo Sacconi
- Institute of Clinical Physiology (IFC-CNR), Florence, Italy.
- Institute for Experimental Cardiovascular Medicine, University Heart Center and Medical Faculty, University of Freiburg, Freiburg, Germany.
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Haq KT, Roberts A, Berk F, Allen S, Swift LM, Posnack NG. KairoSight-3.0: A validated optical mapping software to characterize cardiac electrophysiology, excitation-contraction coupling, and alternans. JOURNAL OF MOLECULAR AND CELLULAR CARDIOLOGY PLUS 2023; 5:100043. [PMID: 37786807 PMCID: PMC10544851 DOI: 10.1016/j.jmccpl.2023.100043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
Background Cardiac optical mapping is an imaging technique that measures fluorescent signals across a cardiac preparation. Dual optical imaging of voltage-sensitive and calcium-sensitive probes allows for simultaneous recordings of cardiac action potentials and intracellular calcium transients with high spatiotemporal resolution. The analysis of these complex optical datasets is both time intensive and technically challenging; as such, we have developed a software package for semi-automated image processing and analysis. Herein, we report an updated version of our software package (KairoSight-3.0) with features to enhance the characterization of cardiac parameters using optical signals. Methods To test software validity and applicability, we used Langendorff-perfused heart preparations to record transmembrane voltage and intracellular calcium signals from the epicardial surface. Isolated hearts from guinea pigs and rats were loaded with a potentiometric dye (RH237) and/or calcium indicator dye (Rhod-2AM) and fluorescent signals were acquired. We used Python 3.8.5 programming language to develop the KairoSight-3.0 software. Cardiac maps were validated with a user-specified manual mapping approach. Results Manual maps of action potential duration (30 or 80 % repolarization), calcium transient duration (30 or 80 % reuptake), action potential and calcium transient alternans were constituted to validate the accuracy of software-generated maps. Manual and software maps had high accuracy, with >97 % of manual and software values falling within 10 ms of each other and >75 % within 5 ms for action potential duration and calcium transient duration measurements (n = 1000-2000 pixels). Further, our software package includes additional measurement tools to analyze signal-to-noise ratio, conduction velocity, action potential and calcium transient alternans, and action potential-calcium transient coupling time to produce physiologically meaningful optical maps. Conclusions KairoSight-3.0 has enhanced capabilities to perform measurements of cardiac electrophysiology, calcium handling, alternans, and the excitation-contraction coupling with satisfactory accuracy.
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Affiliation(s)
- Kazi T. Haq
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Health System, Washington, DC 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, DC 20010, USA
| | - Anysja Roberts
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Health System, Washington, DC 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, DC 20010, USA
| | - Fiona Berk
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Health System, Washington, DC 20010, USA
- Department of Biomedical Engineering, School of Engineering and Applied Sciences: George Washington University, Washington, DC 20037, USA
| | - Samuel Allen
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Health System, Washington, DC 20010, USA
| | - Luther M. Swift
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Health System, Washington, DC 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, DC 20010, USA
| | - Nikki Gillum Posnack
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Health System, Washington, DC 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, DC 20010, USA
- Department of Pediatrics, Department of Pharmacology & Physiology, School of Medicine and Health Sciences: George Washington University, Washington, DC 20037, USA
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Yan P, Acker CD, Biasci V, Judge G, Monroe A, Sacconi L, Loew LM. Near-infrared voltage-sensitive dyes based on chromene donor. Proc Natl Acad Sci U S A 2023; 120:e2305093120. [PMID: 37579138 PMCID: PMC10450434 DOI: 10.1073/pnas.2305093120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 06/29/2023] [Indexed: 08/16/2023] Open
Abstract
Voltage-sensitive dyes (VSDs) are used to image electrical activity in cells and tissues with submillisecond time resolution. Most of these fast sensors are constructed from push-pull chromophores whose fluorescence spectra are modulated by the electric field across the cell membrane. It was found that the substitution of naphthalene with chromene produces a 60 to 80 nm red-shift in absorption and emission spectra while maintaining fluorescence quantum efficiency and voltage sensitivity. One dye was applied to ex vivo murine heart with excitation at 730 nm, by far the longest wavelength reported in voltage imaging. This VSD resolves cardiac action potentials in single trials with 12% ΔF/F per action potential. The well-separated excitation spectra between these long-wavelength VSDs and channelrhodopsin (ChR2) enabled monitoring of action potential propagation in ChR2 hearts without any perturbation of electrical dynamics. Importantly, by employing spatially localized optogenetic manipulation, action potential dynamics can be assessed in an all-optical fashion with no artifact related to optical cross-talk between the reporter and actuator. These new environmentally sensitive chromene-based chromophores are also likely to have applications outside voltage imaging.
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Affiliation(s)
- Ping Yan
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT06030
| | - Corey D. Acker
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT06030
| | - Valentina Biasci
- European Laboratory for Non-Linear Spectroscopy, University of Florence, Sesto Fiorentino50019, Italy
| | - Giuliana Judge
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT06030
| | - Alexa Monroe
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT06030
| | - Leonardo Sacconi
- Institute of Clinical Physiology, National Research Council, Florence50139, Italy
- Institute for Experimental Cardiovascular Medicine, Faculty of Medicine, University of Freiburg, Freiburg79110, Germany
| | - Leslie M. Loew
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT06030
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9
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Iravanian S, Uzelac I, Shah AD, Toye MJ, Lloyd MS, Burke MA, Daneshmand MA, Attia TS, Vega JD, El-Chami M, Merchant FM, Cherry EM, Bhatia NK, Fenton FH. Higher-Order Dynamics Beyond Repolarization Alternans in Ex-Vivo Human Ventricles are Independent of the Restitution Properties. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.08.16.23293853. [PMID: 37662394 PMCID: PMC10473769 DOI: 10.1101/2023.08.16.23293853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Background Repolarization alternans, defined as period-2 oscillation in the repolarization phase of the action potentials, provides a mechanistic link between cellular dynamics and ventricular fibrillation (VF). Theoretically, higher-order periodicities (e.g., periods 4, 6, 8,...) are expected but have minimal experimental evidence. Methods We studied explanted human hearts obtained from recipients of heart transplantation at the time of surgery. Optical mapping of the transmembrane potential was performed after staining the hearts with voltage-sensitive fluorescent dyes. Hearts were stimulated at an increasing rate until VF was induced. Signals recorded from the right ventricle endocardial surface prior to induction of VF and in the presence of 1:1 conduction were processed using the Principal Component Analysis and a combinatorial algorithm to detect and quantify higher-order dynamics. Results were correlated to the underlying electrophysiological characteristics as quantified by restitution curves and conduction velocity. Results A prominent and statistically significant global 1:4 peak (corresponding to period-4 dynamics) was seen in three of the six studied hearts. Local (pixel-wise) analysis revealed the spatially heterogeneous distribution of periods 4, 6, and 8, with the regional presence of periods greater than two in all the hearts. There was no significant correlation between the underlying restitution properties and the period of each pixel. Discussion We present evidence of higher-order periodicities and the co-existence of such regions with stable non-chaotic areas in ex-vivo human hearts. We infer from the independence of the period to the underlying restitution properties that the oscillation of the excitation-contraction coupling and calcium cycling mechanisms is the primary mechanism of higher-order dynamics. These higher-order regions may act as niduses of instability that can degenerate into chaotic fibrillation and may provide targets for substrate-based ablation of VF.
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Affiliation(s)
- Shahriar Iravanian
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | - Ilija Uzelac
- Georgia Tech, Department of Physics, Atlanta, GA
| | - Anand D Shah
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | | | - Michael S. Lloyd
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | - Michael A. Burke
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | - Mani A Daneshmand
- Division of Cardiovascular Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA
| | - Tamer S Attia
- Division of Cardiovascular Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA
| | - J David Vega
- Division of Cardiovascular Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA
| | - Michael El-Chami
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | - Faisal M. Merchant
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | | | - Neal K. Bhatia
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
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Zhang H, Patton HN, Wood GA, Yan P, Loew LM, Acker CD, Walcott GP, Rogers JM. Di-5-ANEQ(F)PTEA Offers Better Performance than Di-4-ANEQ(F)PTEA for In-Situ Cardiac Optical Mapping . ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-4. [PMID: 38082915 DOI: 10.1109/embc40787.2023.10340445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Cardiac optical mapping has traditionally been performed in ex-vivo, motion-arrested hearts. Recently, in-situ cardiac optical mapping has been made possible by both motion correction techniques and long-wavelength voltage sensitive dyes (VSDs). However, VSDs have been observed to wash out quickly from blood-perfused in-situ hearts. In this study, we evaluate the performance of a newly developed VSD, di-5-ANEQ(F)PTEA, relative to an earlier VSD, di-4-ANEQ(F)PTEA. We find that di-5-ANEQ(F)PTEA persists over 3 times longer, produces improved signal-to-noise ratio, and does not prolong loading unacceptably.Clinical Relevance-Optical mapping has provided many insights into cardiac arrhythmias, but has traditionally been limited to ex-vivo preparations. The present findings extend the utility of optical mapping in the more realistic in-vivo setting and may eventually enable its use in patients.
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11
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Marchal GA, Biasci V, Loew LM, Biggeri A, Campione M, Sacconi L. Optogenetic manipulation of cardiac repolarization gradients using sub-threshold illumination. Front Physiol 2023; 14:1167524. [PMID: 37215182 PMCID: PMC10196067 DOI: 10.3389/fphys.2023.1167524] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 04/24/2023] [Indexed: 05/24/2023] Open
Abstract
Introduction: Mechanisms underlying cardiac arrhythmias are typically driven by abnormalities in cardiac conduction and/or heterogeneities in repolarization time (RT) across the heart. While conduction slowing can be caused by either electrophysiological defects or physical blockade in cardiac tissue, RT heterogeneities are mainly related to action potential (AP) prolongation or abbreviation in specific areas of the heart. Importantly, the size of the area with altered RT and the difference between the short RT and long RT (RT gradient) have been identified as critical determinators of arrhythmogenicity. However, current experimental methods for manipulating RT gradient rely on the use of ion channel inhibitors, which lack spatial and temporal specificity and are commonly only partially reversible. Therefore, the conditions facilitating sustained arrhythmia upon the presence of RT heterogeneities and/or defects in cardiac conduction remain to be elucidated. Methods: We here employ an approach based on optogenetic stimulation in a low-intensity fashion (sub-threshold illumination), to selectively manipulate cardiac electrical activity in defined areas of the heart. Results: As previously described, subthreshold illumination is a robust tool able to prolong action potentials (AP), decrease upstroke velocity as well as slow cardiac conduction, in a fully reversible manner. By applying a patterned sub-threshold illumination in intact mouse hearts constitutively expressing the light-gated ion channel channelrhodopsin-2 (ChR2), we optically manipulate RT gradients and cardiac conduction across the heart in a spatially selective manner. Moreover, in a proof-of-concept assessment we found that in the presence of patterned sub-threshold illumination, mouse hearts were more susceptible to arrhythmias. Hence, this optogenetic-based approach may be able to mimic conduction slowing and RT heterogeneities present in pathophysiological conditions.
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Affiliation(s)
- Gerard A. Marchal
- European Laboratory for Non-Linear Spectroscopy—LENS, Florence, Italy
- National Institute of Optics (INO-CNR), Florence, Italy
- Institute of Clinical Physiology (IFC-CNR), Pisa, Italy
| | - Valentina Biasci
- European Laboratory for Non-Linear Spectroscopy—LENS, Florence, Italy
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Leslie M. Loew
- Center for Cell Analysis and Modeling, University of Connecticut, Farmington, CT, United States
| | - Annibale Biggeri
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padua, Padua, Italy
| | - Marina Campione
- Institute of Neuroscience (IN-CNR) and Department of Biomedical Science University of Padua, Padua, Italy
| | - Leonardo Sacconi
- Institute of Clinical Physiology (IFC-CNR), Pisa, Italy
- Institute for Experimental Cardiovascular Medicine, University Heart Center and Medical Faculty, University of Freiburg, Freiburg, Germany
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12
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Haq KT, Roberts A, Berk F, Allen S, Swift LM, Posnack NG. KairoSight-3.0 : A Validated Optical Mapping Software to Characterize Cardiac Electrophysiology, Excitation-Contraction Coupling, and Alternans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.01.538926. [PMID: 37205349 PMCID: PMC10187248 DOI: 10.1101/2023.05.01.538926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Background Cardiac optical mapping is an imaging technique that measures fluorescent signals across a cardiac preparation. Dual optical mapping of voltage-sensitive and calcium-sensitive probes allow for simultaneous recordings of cardiac action potentials and intracellular calcium transients with high spatiotemporal resolution. The analysis of these complex optical datasets is both time intensive and technically challenging; as such, we have developed a software package for semi-automated image processing and analysis. Herein, we report an updated version of our software package ( KairoSight-3 . 0 ) with features to enhance characterization of cardiac parameters using optical signals. Methods To test software validity and applicability, we used Langendorff-perfused heart preparations to record transmembrane voltage and intracellular calcium signals from the epicardial surface. Isolated hearts from guinea pigs and rats were loaded with a potentiometric dye (RH237) and/or calcium indicator dye (Rhod-2AM) and fluorescent signals were acquired. We used Python 3.8.5 programming language to develop the KairoSight-3 . 0 software. Cardiac maps were validated with a user-specified manual mapping approach. Results Manual maps of action potential duration (30 or 80% repolarization), calcium transient duration (30 or 80% reuptake), action potential and calcium transient alternans were constituted to validate the accuracy of software-generated maps. Manual and software maps had high accuracy, with >97% of manual and software values falling within 10 ms of each other and >75% within 5 ms for action potential duration and calcium transient duration measurements (n=1000-2000 pixels). Further, our software package includes additional cardiac metric measurement tools to analyze signal-to-noise ratio, conduction velocity, action potential and calcium transient alternans, and action potential-calcium transient coupling time to produce physiologically meaningful optical maps. Conclusions KairoSight-3 . 0 has enhanced capabilities to perform measurements of cardiac electrophysiology, calcium handling, and the excitation-contraction coupling with satisfactory accuracy. Graphical Abstract Demonstrating Experimental and Data Analysis Workflow Created with Biorender.com.
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13
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Iravanian S, Uzelac I, Shah AD, Toye MJ, Lloyd MS, Burke MA, Daneshmand MA, Attia TS, Vega JD, Merchant FM, Cherry EM, Bhatia NK, Fenton FH. Beyond Alternans: Detection of Higher-Order Periodicity in Ex-Vivo Human Ventricles Before Induction of Ventricular Fibrillation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.01.539003. [PMID: 37205562 PMCID: PMC10187180 DOI: 10.1101/2023.05.01.539003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Background Repolarization alternans, defined as period-2 oscillation in the repolarization phase of the action potentials, is one of the cornerstones of cardiac electrophysiology as it provides a mechanistic link between cellular dynamics and ventricular fibrillation (VF). Theoretically, higher-order periodicities (e.g., period-4, period-8,...) are expected but have very limited experimental evidence. Methods We studied explanted human hearts, obtained from the recipients of heart transplantation at the time of surgery, using optical mapping technique with transmembrane voltage-sensitive fluorescent dyes. The hearts were stimulated at an increasing rate until VF was induced. The signals recorded from the right ventricle endocardial surface just before the induction of VF and in the presence of 1:1 conduction were processed using the Principal Component Analysis and a combinatorial algorithm to detect and quantify higher-order dynamics. Results A prominent and statistically significant 1:4 peak (corresponding to period-4 dynamics) was seen in three of the six studied hearts. Local analysis revealed the spatiotemporal distribution of higher-order periods. Period-4 was localized to temporally stable islands. Higher-order oscillations (period-5, 6, and 8) were transient and primarily occurred in arcs parallel to the activation isochrones. Discussion We present evidence of higher-order periodicities and the co-existence of such regions with stable non-chaotic areas in ex-vivo human hearts before VF induction. This result is consistent with the period-doubling route to chaos as a possible mechanism of VF initiation, which complements the concordant to discordant alternans mechanism. The presence of higher-order regions may act as niduses of instability that can degenerate into chaotic fibrillation.
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14
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Kappadan V, Sohi A, Parlitz U, Luther S, Uzelac I, Fenton F, Peters NS, Christoph J, Ng FS. Optical mapping of contracting hearts. J Physiol 2023; 601:1353-1370. [PMID: 36866700 PMCID: PMC10952556 DOI: 10.1113/jp283683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 02/27/2023] [Indexed: 03/04/2023] Open
Abstract
Optical mapping is a widely used tool to record and visualize the electrophysiological properties in a variety of myocardial preparations such as Langendorff-perfused isolated hearts, coronary-perfused wedge preparations, and cell culture monolayers. Motion artifact originating from the mechanical contraction of the myocardium creates a significant challenge to performing optical mapping of contracting hearts. Hence, to minimize the motion artifact, cardiac optical mapping studies are mostly performed on non-contracting hearts, where the mechanical contraction is removed using pharmacological excitation-contraction uncouplers. However, such experimental preparations eliminate the possibility of electromechanical interaction, and effects such as mechano-electric feedback cannot be studied. Recent developments in computer vision algorithms and ratiometric techniques have opened the possibility of performing optical mapping studies on isolated contracting hearts. In this review, we discuss the existing techniques and challenges of optical mapping of contracting hearts.
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Affiliation(s)
- Vineesh Kappadan
- National Heart and Lung Institute (NHLI)Imperial College LondonLondonUK
| | - Anies Sohi
- National Heart and Lung Institute (NHLI)Imperial College LondonLondonUK
| | - Ulrich Parlitz
- Biomedical Physcis GroupMax Planck Institute for Dynamics and Self‐OrganizationGöttingenGermany
| | - Stefan Luther
- Biomedical Physcis GroupMax Planck Institute for Dynamics and Self‐OrganizationGöttingenGermany
| | - Ilija Uzelac
- School of PhysicsGeorgia Institute of TechnologyAtlantaGAUSA
| | - Flavio Fenton
- School of PhysicsGeorgia Institute of TechnologyAtlantaGAUSA
| | - Nicholas S Peters
- National Heart and Lung Institute (NHLI)Imperial College LondonLondonUK
| | - Jan Christoph
- Cardiovascular Research InstituteUniversity of CaliforniaSan FranciscoCAUSA
| | - Fu Siong Ng
- National Heart and Lung Institute (NHLI)Imperial College LondonLondonUK
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15
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Ramlugun GS, Kulkarni K, Pallares-Lupon N, Boukens BJ, Efimov IR, Vigmond EJ, Bernus O, Walton RD. A comprehensive framework for evaluation of high pacing frequency and arrhythmic optical mapping signals. Front Physiol 2023; 14:734356. [PMID: 36755791 PMCID: PMC9901579 DOI: 10.3389/fphys.2023.734356] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 01/09/2023] [Indexed: 01/24/2023] Open
Abstract
Introduction: High pacing frequency or irregular activity due to arrhythmia produces complex optical mapping signals and challenges for processing. The objective is to establish an automated activation time-based analytical framework applicable to optical mapping images of complex electrical behavior. Methods: Optical mapping signals with varying complexity from sheep (N = 7) ventricular preparations were examined. Windows of activation centered on each action potential upstroke were derived using Hilbert transform phase. Upstroke morphology was evaluated for potential multiple activation components and peaks of upstroke signal derivatives defined activation time. Spatially and temporally clustered activation time points were grouped in to wave fronts for individual processing. Each activation time point was evaluated for corresponding repolarization times. Each wave front was subsequently classified based on repetitive or non-repetitive events. Wave fronts were evaluated for activation time minima defining sites of wave front origin. A visualization tool was further developed to probe dynamically the ensemble activation sequence. Results: Our framework facilitated activation time mapping during complex dynamic events including transitions to rotor-like reentry and ventricular fibrillation. We showed that using fixed AT windows to extract AT maps can impair interpretation of the activation sequence. However, the phase windowing of action potential upstrokes enabled accurate recapitulation of repetitive behavior, providing spatially coherent activation patterns. We further demonstrate that grouping the spatio-temporal distribution of AT points in to coherent wave fronts, facilitated interpretation of isolated conduction events, such as conduction slowing, and to derive dynamic changes in repolarization properties. Focal origins precisely detected sites of stimulation origin and breakthrough for individual wave fronts. Furthermore, a visualization tool to dynamically probe activation time windows during reentry revealed a critical single static line of conduction slowing associated with the rotation core. Conclusion: This comprehensive analytical framework enables detailed quantitative assessment and visualization of complex electrical behavior.
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Affiliation(s)
- Girish S. Ramlugun
- IHU-Liryc, Fondation Bordeaux Université, Pessac-Bordeaux, France,Univ. Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique, Bordeaux, France
| | - Kanchan Kulkarni
- IHU-Liryc, Fondation Bordeaux Université, Pessac-Bordeaux, France,Univ. Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique, Bordeaux, France
| | - Nestor Pallares-Lupon
- IHU-Liryc, Fondation Bordeaux Université, Pessac-Bordeaux, France,Univ. Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique, Bordeaux, France
| | - Bastiaan J. Boukens
- Department of Physiology, Cardiovascular Research Institute Maastricht, University Maastricht, Maastricht, Netherlands,Department of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Igor R. Efimov
- Department of Biomedical Engineering, The George Washington University, Washington, DC, United States,Department of Biomedical Engineering, Northwestern University, Chicago, IL, United States,Department of Medicine, Northwestern University, Chicago, IL, United States
| | - Edward J. Vigmond
- IHU-Liryc, Fondation Bordeaux Université, Pessac-Bordeaux, France,Univ. Bordeaux, Centre National de la Recherche Scientifique (CNRS), Institut de Mathématiques de Bordeaux, UMR5251, Bordeaux, France
| | - Olivier Bernus
- IHU-Liryc, Fondation Bordeaux Université, Pessac-Bordeaux, France,Univ. Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique, Bordeaux, France
| | - Richard D. Walton
- IHU-Liryc, Fondation Bordeaux Université, Pessac-Bordeaux, France,Univ. Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique, Bordeaux, France,*Correspondence: Richard D. Walton,
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16
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Amesz JH, Zhang L, Everts BR, De Groot NMS, Taverne YJHJ. Living myocardial slices: Advancing arrhythmia research. Front Physiol 2023; 14:1076261. [PMID: 36711023 PMCID: PMC9880234 DOI: 10.3389/fphys.2023.1076261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 01/04/2023] [Indexed: 01/15/2023] Open
Abstract
Living myocardial slices (LMS) are ultrathin (150-400 µm) sections of intact myocardium that can be used as a comprehensive model for cardiac arrhythmia research. The recent introduction of biomimetic electromechanical cultivation chambers enables long-term cultivation and easy control of living myocardial slices culture conditions. The aim of this review is to present the potential of this biomimetic interface using living myocardial slices in electrophysiological studies outlining advantages, disadvantages and future perspectives of the model. Furthermore, different electrophysiological techniques and their application on living myocardial slices will be discussed. The developments of living myocardial slices in electrophysiology research will hopefully lead to future breakthroughs in the understanding of cardiac arrhythmia mechanisms and the development of novel therapeutic options.
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Affiliation(s)
- Jorik H. Amesz
- Translational Cardiothoracic Surgery Research Lab, Lowlands Institute for Bioelectric Medicine, Department of Cardiothoracic Surgery, Erasmus University Medical Center, Rotterdam, Netherlands,Translational Electrophysiology, Lowlands Institute for Bioelectric Medicine, Department of Cardiology, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Lu Zhang
- Translational Electrophysiology, Lowlands Institute for Bioelectric Medicine, Department of Cardiology, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Bian R. Everts
- Translational Cardiothoracic Surgery Research Lab, Lowlands Institute for Bioelectric Medicine, Department of Cardiothoracic Surgery, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Natasja M. S. De Groot
- Translational Electrophysiology, Lowlands Institute for Bioelectric Medicine, Department of Cardiology, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Yannick J. H. J. Taverne
- Translational Cardiothoracic Surgery Research Lab, Lowlands Institute for Bioelectric Medicine, Department of Cardiothoracic Surgery, Erasmus University Medical Center, Rotterdam, Netherlands,*Correspondence: Yannick J. H. J. Taverne,
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17
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Heinson YW, Han JL, Entcheva E. Portable low-cost macroscopic mapping system for all-optical cardiac electrophysiology. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:016001. [PMID: 36636698 PMCID: PMC9830584 DOI: 10.1117/1.jbo.28.1.016001] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 12/19/2022] [Indexed: 05/10/2023]
Abstract
SIGNIFICANCE All-optical cardiac electrophysiology enables the visualization and control of key parameters relevant to the detection of cardiac arrhythmias. Mapping such responses in human induced pluripotent stem-cell-derived cardiomyocytes (hiPSC-CMs) is of great interest for cardiotoxicity and personalized medicine applications. AIM We introduce and validate a very low-cost compact mapping system for macroscopic all-optical electrophysiology in layers of hiPSC-CMs. APPROACH The system uses oblique transillumination, low-cost cameras, light-emitting diodes, and off-the-shelf components (total < $ 15 , 000 ) to capture voltage, calcium, and mechanical waves under electrical or optical stimulation. RESULTS Our results corroborate the equivalency of electrical and optogenetic stimulation of hiPSC-CMs, and V m - [ Ca 2 + ] i similarity in conduction under pacing. Green-excitable optical sensors are combinable with blue optogenetic actuators (chanelrhodopsin2) only under very low green light ( < 0.05 mW / mm 2 ). Measurements in warmer culture medium yield larger spread of action potential duration and higher conduction velocities compared to Tyrode's solution at room temperature. CONCLUSIONS As multiple optical sensors and actuators are combined, our results can help handle the "spectral congestion" and avoid parameter distortion. We illustrate the utility of the system for uncovering the action of cellular uncoupling agents and show extensibility to an epi-illumination mode for future imaging of thicker native or engineered tissues.
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Affiliation(s)
- Yuli W. Heinson
- George Washington University, Department of Biomedical Engineering, Washington, DC, United States
| | - Julie L. Han
- George Washington University, Department of Biomedical Engineering, Washington, DC, United States
| | - Emilia Entcheva
- George Washington University, Department of Biomedical Engineering, Washington, DC, United States
- Address all correspondence to Emilia Entcheva,
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18
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Ripplinger CM, Glukhov AV, Kay MW, Boukens BJ, Chiamvimonvat N, Delisle BP, Fabritz L, Hund TJ, Knollmann BC, Li N, Murray KT, Poelzing S, Quinn TA, Remme CA, Rentschler SL, Rose RA, Posnack NG. Guidelines for assessment of cardiac electrophysiology and arrhythmias in small animals. Am J Physiol Heart Circ Physiol 2022; 323:H1137-H1166. [PMID: 36269644 PMCID: PMC9678409 DOI: 10.1152/ajpheart.00439.2022] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Cardiac arrhythmias are a major cause of morbidity and mortality worldwide. Although recent advances in cell-based models, including human-induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM), are contributing to our understanding of electrophysiology and arrhythmia mechanisms, preclinical animal studies of cardiovascular disease remain a mainstay. Over the past several decades, animal models of cardiovascular disease have advanced our understanding of pathological remodeling, arrhythmia mechanisms, and drug effects and have led to major improvements in pacing and defibrillation therapies. There exist a variety of methodological approaches for the assessment of cardiac electrophysiology and a plethora of parameters may be assessed with each approach. This guidelines article will provide an overview of the strengths and limitations of several common techniques used to assess electrophysiology and arrhythmia mechanisms at the whole animal, whole heart, and tissue level with a focus on small animal models. We also define key electrophysiological parameters that should be assessed, along with their physiological underpinnings, and the best methods with which to assess these parameters.
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Affiliation(s)
- Crystal M. Ripplinger
- 1Department of Pharmacology, University of California Davis School of Medicine, Davis, California
| | - Alexey V. Glukhov
- 2Department of Medicine, Cardiovascular Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Matthew W. Kay
- 3Department of Biomedical Engineering, The George Washington University, Washington, District of Columbia
| | - Bastiaan J. Boukens
- 4Department Physiology, University Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands,5Department of Medical Biology, University of Amsterdam, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Nipavan Chiamvimonvat
- 1Department of Pharmacology, University of California Davis School of Medicine, Davis, California,6Department of Internal Medicine, University of California Davis School of Medicine, Davis, California,7Veterans Affairs Northern California Healthcare System, Mather, California
| | - Brian P. Delisle
- 8Department of Physiology, University of Kentucky, Lexington, Kentucky
| | - Larissa Fabritz
- 9University Center of Cardiovascular Science, University Heart and Vascular Center, University Hospital Hamburg-Eppendorf with DZHK Hamburg/Kiel/Luebeck, Germany,10Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Thomas J. Hund
- 11Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio,12Department of Biomedical Engineering, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
| | - Bjorn C. Knollmann
- 13Vanderbilt Center for Arrhythmia Research and Therapeutics, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Na Li
- 14Department of Medicine, Baylor College of Medicine, Houston, Texas
| | - Katherine T. Murray
- 15Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Steven Poelzing
- 16Virginia Tech Carilon School of Medicine, Center for Heart and Reparative Medicine Research, Fralin Biomedical Research Institute at Virginia Tech, Roanoke, Virginia,17Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia
| | - T. Alexander Quinn
- 18Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada,19School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Carol Ann Remme
- 20Department of Experimental Cardiology, Heart Centre, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
| | - Stacey L. Rentschler
- 21Cardiovascular Division, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri
| | - Robert A. Rose
- 22Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada,23Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Nikki G. Posnack
- 24Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, Washington, District of Columbia,25Department of Pediatrics, George Washington University School of Medicine, Washington, District of Columbia
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19
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Xu D, Fang J, Wang H, Wei X, Yang J, Li H, Yang T, Li Y, Liu C, Hu N. Scalable Nanotrap Matrix Enhanced Electroporation for Intracellular Recording of Action Potential. NANO LETTERS 2022; 22:7467-7476. [PMID: 36069674 DOI: 10.1021/acs.nanolett.2c02398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Electrophysiological recording, as a long-sought objective, plays a crucial role in fundamental biomedical research and practical clinical applications. The challenge in developing electrophysiological detection platforms is to combine simplicity, stability, and sensitivity in the same device. In this study, we develop a nanotrapped microelectrode based on a porous PET membrane, which is compatible with large-scale microtechnologies. The nanotraps can promote the protrusion of the local cell membrane in the hollow center and offer a unique nanoedge structure for tight sealing and effective electroporation. We demonstrate that scalable nanotraps can enhance cell-electrode coupling and perform high-quality intracellular recording. Further, the nanoedge-enhanced electroporation and minimally invasive nanotrapped recordings afford much longer intracellular access of over 100 min and permit consecutive electroporation events in a short period of time. This study suggests that the geometry-regulating strategy of the cell-electrode nanointerface could significantly improve the intracellular recording performance of a nanopatterned electrode.
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Affiliation(s)
- Dongxin Xu
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510006, People's Republic of China
| | - Jiaru Fang
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510006, People's Republic of China
| | - Hao Wang
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510006, People's Republic of China
| | - Xinwei Wei
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou 311200, People's Republic of China
| | - Jinhu Yang
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510006, People's Republic of China
| | - Hongbo Li
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510006, People's Republic of China
| | - Tao Yang
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510006, People's Republic of China
| | - Ying Li
- College of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, People's Republic of China
| | - Chuan Liu
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510006, People's Republic of China
| | - Ning Hu
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510006, People's Republic of China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou 311200, People's Republic of China
- Stoddart Institute of Molecular Science, Department of Chemistry, Zhejiang University, Hangzhou 310027, People's Republic of China
- State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China
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20
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Sung YL, Wang TW, Lin TT, Lin SF. Optogenetics in cardiology: methodology and future applications. INTERNATIONAL JOURNAL OF ARRHYTHMIA 2022. [DOI: 10.1186/s42444-022-00060-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
AbstractOptogenetics is an emerging biological approach with the unique capability of specific targeting due to the precise light control with high spatial and temporal resolution. It uses selected light wavelengths to control and modulate the biological functions of cells, tissues, and organ levels. Optogenetics has been instrumental in different biomedical applications, including neuroscience, diabetes, and mitochondria, based on distinctive optical biomedical effects with light modulation. Nowadays, optogenetics in cardiology is rapidly evolving for the understanding and treatment of cardiovascular diseases. Several in vitro and in vivo research for cardiac optogenetics demonstrated visible progress. The optogenetics technique can be applied to address critical cardiovascular problems such as heart failure and arrhythmia. To this end, this paper reviews cardiac electrophysiology and the technical progress about experimental and clinical cardiac optogenetics and provides the background and evolution of cardiac optogenetics. We reviewed the literature to demonstrate the servo type, transfection efficiency, signal recording, and heart disease targets in optogenetic applications. Such literature review would hopefully expedite the progress of optogenetics in cardiology and further expect to translate into the clinical terminal in the future.
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21
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Sacconi L, Silvestri L, Rodríguez EC, Armstrong GA, Pavone FS, Shrier A, Bub G. KHz-rate volumetric voltage imaging of the whole Zebrafish heart. BIOPHYSICAL REPORTS 2022; 2:100046. [PMID: 36425080 PMCID: PMC9680780 DOI: 10.1016/j.bpr.2022.100046] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 01/31/2022] [Indexed: 05/11/2023]
Abstract
Fast volumetric imaging is essential for understanding the function of excitable tissues such as those found in the brain and heart. Measuring cardiac voltage transients in tissue volumes is challenging, especially at the high spatial and temporal resolutions needed to give insight to cardiac function. We introduce a new imaging modality based on simultaneous illumination of multiple planes in the tissue and parallel detection with multiple cameras, avoiding compromises inherent in any scanning approach. The system enables imaging of voltage transients in situ, allowing us, for the first time to our knowledge, to map voltage activity in the whole heart volume at KHz rates. The high spatiotemporal resolution of our method enabled the observation of novel dynamics of electrical propagation through the zebrafish atrioventricular canal.
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Affiliation(s)
- Leonardo Sacconi
- European Laboratory for Non-linear Spectroscopy, and National Institute of Optics, National Research Council, Sesto Fiorentino, Italy
- Institute for Experimental Cardiovascular Medicine, University Heart Center and Medical Faculty, University of Freiburg, Freiburg, Germany
- Corresponding author
| | - Ludovico Silvestri
- European Laboratory for Non-linear Spectroscopy, and National Institute of Optics, National Research Council, Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, Florence, Italy
| | | | - Gary A.B. Armstrong
- Department of Neurology and Neurosurgery, McGill University, Montreal, Canada
| | - Francesco S. Pavone
- European Laboratory for Non-linear Spectroscopy, and National Institute of Optics, National Research Council, Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, Florence, Italy
| | - Alvin Shrier
- Department of Physiology, McGill University, Montreal, Canada
| | - Gil Bub
- Department of Physiology, McGill University, Montreal, Canada
- Corresponding author
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22
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Human iPSC-Cardiomyocytes as an Experimental Model to Study Epigenetic Modifiers of Electrophysiology. Cells 2022; 11:cells11020200. [PMID: 35053315 PMCID: PMC8774228 DOI: 10.3390/cells11020200] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/31/2021] [Accepted: 01/01/2022] [Indexed: 02/04/2023] Open
Abstract
The epigenetic landscape and the responses to pharmacological epigenetic regulators in each human are unique. Classes of epigenetic writers and erasers, such as histone acetyltransferases, HATs, and histone deacetylases, HDACs, control DNA acetylation/deacetylation and chromatin accessibility, thus exerting transcriptional control in a tissue- and person-specific manner. Rapid development of novel pharmacological agents in clinical testing—HDAC inhibitors (HDACi)—targets these master regulators as common means of therapeutic intervention in cancer and immune diseases. The action of these epigenetic modulators is much less explored for cardiac tissue, yet all new drugs need to be tested for cardiotoxicity. To advance our understanding of chromatin regulation in the heart, and specifically how modulation of DNA acetylation state may affect functional electrophysiological responses, human-induced pluripotent stem-cell-derived cardiomyocyte (hiPSC-CM) technology can be leveraged as a scalable, high-throughput platform with ability to provide patient-specific insights. This review covers relevant background on the known roles of HATs and HDACs in the heart, the current state of HDACi development, applications, and any adverse cardiac events; it also summarizes relevant differential gene expression data for the adult human heart vs. hiPSC-CMs along with initial transcriptional and functional results from using this new experimental platform to yield insights on epigenetic control of the heart. We focus on the multitude of methodologies and workflows needed to quantify responses to HDACis in hiPSC-CMs. This overview can help highlight the power and the limitations of hiPSC-CMs as a scalable experimental model in capturing epigenetic responses relevant to the human heart.
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23
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Optogenetic manipulation of cardiac electrical dynamics using sub-threshold illumination: dissecting the role of cardiac alternans in terminating rapid rhythms. Basic Res Cardiol 2022; 117:25. [PMID: 35488105 PMCID: PMC9054908 DOI: 10.1007/s00395-022-00933-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 04/01/2022] [Accepted: 04/18/2022] [Indexed: 02/01/2023]
Abstract
Cardiac action potential (AP) shape and propagation are regulated by several key dynamic factors such as ion channel recovery and intracellular Ca2+ cycling. Experimental methods for manipulating AP electrical dynamics commonly use ion channel inhibitors that lack spatial and temporal specificity. In this work, we propose an approach based on optogenetics to manipulate cardiac electrical activity employing a light-modulated depolarizing current with intensities that are too low to elicit APs (sub-threshold illumination), but are sufficient to fine-tune AP electrical dynamics. We investigated the effects of sub-threshold illumination in isolated cardiomyocytes and whole hearts by using transgenic mice constitutively expressing a light-gated ion channel (channelrhodopsin-2, ChR2). We find that ChR2-mediated depolarizing current prolongs APs and reduces conduction velocity (CV) in a space-selective and reversible manner. Sub-threshold manipulation also affects the dynamics of cardiac electrical activity, increasing the magnitude of cardiac alternans. We used an optical system that uses real-time feedback control to generate re-entrant circuits with user-defined cycle lengths to explore the role of cardiac alternans in spontaneous termination of ventricular tachycardias (VTs). We demonstrate that VT stability significantly decreases during sub-threshold illumination primarily due to an increase in the amplitude of electrical oscillations, which implies that cardiac alternans may be beneficial in the context of self-termination of VT.
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24
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Swift LM, Kay MW, Ripplinger CM, Posnack NG. Stop the beat to see the rhythm: excitation-contraction uncoupling in cardiac research. Am J Physiol Heart Circ Physiol 2021; 321:H1005-H1013. [PMID: 34623183 DOI: 10.1152/ajpheart.00477.2021] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Optical mapping is an imaging technique that is extensively used in cardiovascular research, wherein parameter-sensitive fluorescent indicators are used to study the electrophysiology and excitation-contraction coupling of cardiac tissues. Despite many benefits of optical mapping, eliminating motion artifacts within the optical signals is a major challenge, as myocardial contraction interferes with the faithful acquisition of action potentials and intracellular calcium transients. As such, excitation-contraction uncoupling agents are frequently used to reduce signal distortion by suppressing contraction. When compared with other uncoupling agents, blebbistatin is the most frequently used, as it offers increased potency with minimal direct effects on cardiac electrophysiology. Nevertheless, blebbistatin may exert secondary effects on electrical activity, metabolism, and coronary flow, and the incorrect administration of blebbistatin to cardiac tissue can prove detrimental, resulting in erroneous interpretation of optical mapping results. In this "Getting It Right" perspective, we briefly review the literature regarding the use of blebbistatin in cardiac optical mapping experiments, highlight potential secondary effects of blebbistatin on cardiac electrical activity and metabolic demand, and conclude with the consensus of the authors on best practices for effectively using blebbistatin in optical mapping studies of cardiac tissue.
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Affiliation(s)
- Luther M Swift
- Children's National Heart Institute, Children's National Hospital, Washington, District of Columbia.,Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, District of Columbia
| | - Matthew W Kay
- Department of Biomedical Engineering, George Washington University, Washington, District of Columbia
| | | | - Nikki Gillum Posnack
- Children's National Heart Institute, Children's National Hospital, Washington, District of Columbia.,Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, District of Columbia.,Department of Pediatrics, George Washington University, Washington, District of Columbia.,Department of Pharmacology and Physiology, George Washington University, Washington, District of Columbia
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25
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Cooper BL, Gloschat C, Swift LM, Prudencio T, McCullough D, Jaimes R, Posnack NG. KairoSight: Open-Source Software for the Analysis of Cardiac Optical Data Collected From Multiple Species. Front Physiol 2021; 12:752940. [PMID: 34777017 PMCID: PMC8586513 DOI: 10.3389/fphys.2021.752940] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 09/27/2021] [Indexed: 01/09/2023] Open
Abstract
Cardiac optical mapping, also known as optocardiography, employs parameter-sensitive fluorescence dye(s) to image cardiac tissue and resolve the electrical and calcium oscillations that underly cardiac function. This technique is increasingly being used in conjunction with, or even as a replacement for, traditional electrocardiography. Over the last several decades, optical mapping has matured into a “gold standard” for cardiac research applications, yet the analysis of optical signals can be challenging. Despite the refinement of software tools and algorithms, significant programming expertise is often required to analyze large optical data sets, and data analysis can be laborious and time-consuming. To address this challenge, we developed an accessible, open-source software script that is untethered from any subscription-based programming language. The described software, written in python, is aptly named “KairoSight” in reference to the Greek word for “opportune time” (Kairos) and the ability to “see” voltage and calcium signals acquired from cardiac tissue. To demonstrate analysis features and highlight species differences, we employed experimental datasets collected from mammalian hearts (Langendorff-perfused rat, guinea pig, and swine) dyed with RH237 (transmembrane voltage) and Rhod-2, AM (intracellular calcium), as well as human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) dyed with FluoVolt (membrane potential), and Fluo-4, AM (calcium indicator). We also demonstrate cardiac responsiveness to ryanodine (ryanodine receptor modulator) and isoproterenol (beta-adrenergic agonist) and highlight regional differences after an ablation injury. KairoSight can be employed by both basic and clinical scientists to analyze complex cardiac optical mapping datasets without requiring dedicated computer science expertise or proprietary software.
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Affiliation(s)
- Blake L Cooper
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, DC, United States.,Children's National Heart Institute, Children's National Hospital, Washington, DC, United States.,Department of Pharmacology and Physiology, George Washington University, Washington, DC, United States
| | - Chris Gloschat
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, DC, United States.,Children's National Heart Institute, Children's National Hospital, Washington, DC, United States
| | - Luther M Swift
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, DC, United States.,Children's National Heart Institute, Children's National Hospital, Washington, DC, United States
| | - Tomas Prudencio
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, DC, United States.,Children's National Heart Institute, Children's National Hospital, Washington, DC, United States
| | - Damon McCullough
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, DC, United States.,Children's National Heart Institute, Children's National Hospital, Washington, DC, United States
| | - Rafael Jaimes
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, DC, United States.,Children's National Heart Institute, Children's National Hospital, Washington, DC, United States
| | - Nikki G Posnack
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, DC, United States.,Children's National Heart Institute, Children's National Hospital, Washington, DC, United States.,Department of Pharmacology and Physiology, George Washington University, Washington, DC, United States.,Department of Pediatrics, George Washington University, Washington, DC, United States
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26
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Ultrafast four-dimensional imaging of cardiac mechanical wave propagation with sparse optoacoustic sensing. Proc Natl Acad Sci U S A 2021; 118:2103979118. [PMID: 34732573 DOI: 10.1073/pnas.2103979118] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2021] [Indexed: 12/25/2022] Open
Abstract
Propagation of electromechanical waves in excitable heart muscles follows complex spatiotemporal patterns holding the key to understanding life-threatening arrhythmias and other cardiac conditions. Accurate volumetric mapping of cardiac wave propagation is currently hampered by fast heart motion, particularly in small model organisms. Here we demonstrate that ultrafast four-dimensional imaging of cardiac mechanical wave propagation in entire beating murine heart can be accomplished by sparse optoacoustic sensing with high contrast, ∼115-µm spatial and submillisecond temporal resolution. We extract accurate dispersion and phase velocity maps of the cardiac waves and reveal vortex-like patterns associated with mechanical phase singularities that occur during arrhythmic events induced via burst ventricular electric stimulation. The newly introduced cardiac mapping approach is a bold step toward deciphering the complex mechanisms underlying cardiac arrhythmias and enabling precise therapeutic interventions.
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27
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Zhou Y, Ding M, Nagel G, Konrad KR, Gao S. Advances and prospects of rhodopsin-based optogenetics in plant research. PLANT PHYSIOLOGY 2021; 187:572-589. [PMID: 35237820 PMCID: PMC8491038 DOI: 10.1093/plphys/kiab338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/05/2021] [Indexed: 05/20/2023]
Abstract
Microbial rhodopsins have advanced optogenetics since the discovery of channelrhodopsins almost two decades ago. During this time an abundance of microbial rhodopsins has been discovered, engineered, and improved for studies in neuroscience and other animal research fields. Optogenetic applications in plant research, however, lagged largely behind. Starting with light-regulated gene expression, optogenetics has slowly expanded into plant research. The recently established all-trans retinal production in plants now enables the use of many microbial opsins, bringing extra opportunities to plant research. In this review, we summarize the recent advances of rhodopsin-based plant optogenetics and provide a perspective for future use, combined with fluorescent sensors to monitor physiological parameters.
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Affiliation(s)
- Yang Zhou
- Institute of Physiology, Department of Neurophysiology, Biocenter, University of Wuerzburg, Wuerzburg 97070, Germany
| | - Meiqi Ding
- Institute for Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute, Biocenter, University of Wuerzburg, Wuerzburg 97082, Germany
| | - Georg Nagel
- Institute of Physiology, Department of Neurophysiology, Biocenter, University of Wuerzburg, Wuerzburg 97070, Germany
| | - Kai R. Konrad
- Institute for Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute, Biocenter, University of Wuerzburg, Wuerzburg 97082, Germany
| | - Shiqiang Gao
- Institute of Physiology, Department of Neurophysiology, Biocenter, University of Wuerzburg, Wuerzburg 97070, Germany
- Author for communication:
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28
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Credi C, Balducci V, Munagala U, Cianca C, Bigiarini S, de Vries AAF, Loew LM, Pavone FS, Cerbai E, Sartiani L, Sacconi L. Fast Optical Investigation of Cardiac Electrophysiology by Parallel Detection in Multiwell Plates. Front Physiol 2021; 12:692496. [PMID: 34539428 PMCID: PMC8446431 DOI: 10.3389/fphys.2021.692496] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 08/11/2021] [Indexed: 11/13/2022] Open
Abstract
Current techniques for fast characterization of cardiac electrophysiology employ optical technologies to control and monitor action potential features of single cells or cellular monolayers placed in multiwell plates. High-speed investigation capacities are commonly achieved by serially analyzing well after well employing fully automated fluorescence microscopes. Here, we describe an alternative cost-effective optical approach (MULTIPLE) that exploits high-power LED arrays to globally illuminate a culture plate and an sCMOS sensor for parallel detection of the fluorescence coming from multiple wells. MULTIPLE combines optical detection of action potentials using a red-shifted voltage-sensitive fluorescent dye (di-4-ANBDQPQ) with optical stimulation, employing optogenetic actuators, to ensure excitation of cardiomyocytes at constant rates. MULTIPLE was first characterized in terms of interwell uniformity of the illumination intensity and optical detection performance. Then, it was applied for probing action potential features in HL-1 cells (i.e., mouse atrial myocyte-like cells) stably expressing the blue light-activatable cation channel CheRiff. Under proper stimulation conditions, we were able to accurately measure action potential dynamics across a 24-well plate with variability across the whole plate of the order of 10%. The capability of MULTIPLE to detect action potential changes across a 24-well plate was demonstrated employing the selective K v 11.1 channel blocker (E-4031), in a dose titration experiment. Finally, action potential recordings were performed in spontaneous beating human induced pluripotent stem cell derived cardiomyocytes following pharmacological manipulation of their beating frequency. We believe that the simplicity of the presented optical scheme represents a valid complement to sophisticated and expensive state-of-the-art optical systems for high-throughput cardiac electrophysiological investigations.
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Affiliation(s)
- Caterina Credi
- European Laboratory for Non-linear Spectroscopy, Sesto Fiorentino, Italy.,National Institute of Optics, National Research Council, Florence, Italy
| | - Valentina Balducci
- Department of Neurosciences, Psychology, Drugs and Child Health, University of Florence, Florence, Italy
| | - U Munagala
- Department of Neurosciences, Psychology, Drugs and Child Health, University of Florence, Florence, Italy.,Core Research Laboratory, ISPRO, Florence, Italy
| | - C Cianca
- European Laboratory for Non-linear Spectroscopy, Sesto Fiorentino, Italy
| | - S Bigiarini
- European Laboratory for Non-linear Spectroscopy, Sesto Fiorentino, Italy
| | - Antoine A F de Vries
- Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Leiden, Netherlands
| | - Leslie M Loew
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, CT, United States
| | - Francesco S Pavone
- European Laboratory for Non-linear Spectroscopy, Sesto Fiorentino, Italy.,National Institute of Optics, National Research Council, Florence, Italy.,Department of Physics and Astronomy, University of Florence, Sesto Fiorentino, Italy
| | - Elisabetta Cerbai
- European Laboratory for Non-linear Spectroscopy, Sesto Fiorentino, Italy.,Department of Neurosciences, Psychology, Drugs and Child Health, University of Florence, Florence, Italy
| | - Laura Sartiani
- Department of Neurosciences, Psychology, Drugs and Child Health, University of Florence, Florence, Italy
| | - Leonardo Sacconi
- European Laboratory for Non-linear Spectroscopy, Sesto Fiorentino, Italy.,National Institute of Optics, National Research Council, Florence, Italy
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29
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Marina-Breysse M, García-Escolano A, Vila-García J, Reale-Nosei G, Alfonso-Almazán JM, Yan P, Quintanilla JG, Loew LM, Lee P, Filgueiras-Rama D. A Complete and Low-Cost Cardiac Optical Mapping System in Translational Animal Models. Front Physiol 2021; 12:696270. [PMID: 34489722 PMCID: PMC8417781 DOI: 10.3389/fphys.2021.696270] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 08/03/2021] [Indexed: 11/24/2022] Open
Abstract
Clinicians, biologists, physicists, engineers, and computer scientists are coming together to better understand heart disease, which is currently the leading cause of death globally. Optical mapping, a high-speed fluorescence imaging technique that visualizes and measures key cardiac parameters such as action potentials, cytosolic calcium transients, and fibrillation dynamics, is a core research tool that has arisen from such interdisciplinary collaborations. In an effort to broaden its use, especially among clinical scientists and students, we developed a complete and low-cost optical mapping system, including a constant-flow Langendorff perfusion system, which minimizes the economic threshold to widespread use of this powerful tool in cardiac electrophysiology research. The system described here provides high spatiotemporal resolution data about action potentials, intracellular calcium transients and fibrillation wave dynamics in isolated Langendorff-perfused hearts (pigs and rabbits), relevant for translational research. All system components and software elements are fully disclosed with the aim of increasing the use of this affordable and highly versatile tool among clinicians, basic scientists and students wishing to tackle their own research questions with their own customizable systems.
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Affiliation(s)
- Manuel Marina-Breysse
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), Myocardial Pathophysiology Area, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Alba García-Escolano
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.,Escuela Técnica Superior de Ingenieros de Telecomunicación, Universidad Politécnica de Madrid, Madrid, Spain
| | - Joaquín Vila-García
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), Myocardial Pathophysiology Area, Madrid, Spain
| | - Gabriel Reale-Nosei
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), Myocardial Pathophysiology Area, Madrid, Spain
| | - José M Alfonso-Almazán
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), Myocardial Pathophysiology Area, Madrid, Spain
| | - Ping Yan
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT, United States
| | - Jorge G Quintanilla
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), Myocardial Pathophysiology Area, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.,Department of Cardiology, Hospital Clínico San Carlos, Madrid, Spain
| | - Leslie M Loew
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT, United States
| | - Peter Lee
- Essel Research and Development Inc., Toronto, ON, Canada
| | - David Filgueiras-Rama
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), Myocardial Pathophysiology Area, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.,Department of Cardiology, Hospital Clínico San Carlos, Madrid, Spain
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30
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Xu D, Mo J, Xie X, Hu N. In-Cell Nanoelectronics: Opening the Door to Intracellular Electrophysiology. NANO-MICRO LETTERS 2021; 13:127. [PMID: 34138366 PMCID: PMC8124030 DOI: 10.1007/s40820-021-00655-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/13/2021] [Indexed: 05/07/2023]
Abstract
Establishing a reliable electrophysiological recording platform is crucial for cardiology and neuroscience research. Noninvasive and label-free planar multitransistors and multielectrode arrays are conducive to perform the large-scale cellular electrical activity recordings, but the signal attenuation limits these extracellular devices to record subthreshold activities. In recent decade, in-cell nanoelectronics have been rapidly developed to open the door to intracellular electrophysiology. With the unique three-dimensional nanotopography and advanced penetration strategies, high-throughput and high-fidelity action potential like signal recordings is expected to be realized. This review summarizes in-cell nanoelectronics from versatile nano-biointerfaces, penetration strategies, active/passive nanodevices, systematically analyses the applications in electrogenic cells and especially evaluates the influence of nanodevices on the high-quality intracellular electrophysiological signals. Further, the opportunities, challenges and broad prospects of in-cell nanoelectronics are prospected, expecting to promote the development of in-cell electrophysiological platforms to meet the demand of theoretical investigation and clinical application.
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Affiliation(s)
- Dongxin Xu
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510006, People's Republic of China
| | - Jingshan Mo
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510006, People's Republic of China
| | - Xi Xie
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510006, People's Republic of China
- The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China
| | - Ning Hu
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510006, People's Republic of China.
- State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Shanghai, 200050, People's Republic of China.
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31
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Li J, Li H, Rao P, Luo J, Wang X, Wang L. Shining light on cardiac electrophysiology: From detection to intervention, from basic research to translational applications. Life Sci 2021; 274:119357. [PMID: 33737082 DOI: 10.1016/j.lfs.2021.119357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 03/01/2021] [Accepted: 03/08/2021] [Indexed: 10/21/2022]
Abstract
Cardiac arrhythmias are an important group of cardiovascular diseases, which can occur alone or in association with other cardiovascular diseases. The development of cardiac arrhythmias cannot be separated from changes in cardiac electrophysiology, and the investigation and clarification of cardiac electrophysiological changes are beneficial for the treatment of cardiac arrhythmias. However, electrical energy-based pacemakers and defibrillators, which are widely used to treat arrhythmias, still have certain disadvantages. Thereby, optics promises to be used for optical manipulation and its use in biomedicine is increasing. Since visible light is readily absorbed and scattered in living tissues and tissue penetration is shallow, optical modulation for cells and tissues requires conversion media that convert light energy into bioelectrical activity. In this regard, fluorescent dyes, light-sensitive ion channels, and optical nanomaterials can assume this role, the corresponding optical mapping technology, optogenetics technology, and optical systems based on luminescent nanomaterials have been introduced into the research in cardiovascular field and are expected to be new tools for the study and treatment of cardiac arrhythmias. In addition, infrared and near-infrared light has strong tissue penetration, which is one of the excellent options of external trigger for achieving optical modulation, and is also widely used in the study of optical modulation of biological activities. Here, the advantages of optical applications are summarized, the research progresses and emerging applications of optical-based technologies as detection and intervention tools for cardiac electrophysiological are highlighted. Moreover, the prospects for future applications of optics in clinical diagnosis and treatment are discussed.
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Affiliation(s)
- Jianyi Li
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Cardiovascular Research Institute, Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Cardiology, Wuhan 430060, PR China
| | - Haitao Li
- Department of Cardiology, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou 570311, PR China
| | - Panpan Rao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Cardiovascular Research Institute, Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Cardiology, Wuhan 430060, PR China
| | - Junmiao Luo
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Cardiovascular Research Institute, Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Cardiology, Wuhan 430060, PR China
| | - Xi Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Cardiovascular Research Institute, Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Cardiology, Wuhan 430060, PR China.
| | - Long Wang
- Cardiovascular Research Institute, Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Cardiology, Wuhan 430060, PR China; Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China.
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Kostecki GM, Shi Y, Chen CS, Reich DH, Entcheva E, Tung L. Optogenetic current in myofibroblasts acutely alters electrophysiology and conduction of co-cultured cardiomyocytes. Sci Rep 2021; 11:4430. [PMID: 33627695 PMCID: PMC7904933 DOI: 10.1038/s41598-021-83398-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Accepted: 01/27/2021] [Indexed: 01/31/2023] Open
Abstract
Interactions between cardiac myofibroblasts and myocytes may slow conduction and generate spontaneous beating in fibrosis, increasing the chance of life-threatening arrhythmia. While co-culture studies have shown that myofibroblasts can affect cardiomyocyte electrophysiology in vitro, the extent of myofibroblast-myocyte electrical conductance in a syncytium is unknown. In this neonatal rat study, cardiac myofibroblasts were transduced with Channelrhodopsin-2, which allowed acute and selective increase of myofibroblast current, and plated on top of cardiomyocytes. Optical mapping revealed significantly decreased conduction velocity (- 27 ± 6%, p < 10-3), upstroke rate (- 13 ± 4%, p = 0.002), and action potential duration (- 14 ± 7%, p = 0.004) in co-cultures when 0.017 mW/mm2 light was applied, as well as focal spontaneous beating in 6/7 samples and a decreased cycle length (- 36 ± 18%, p = 0.002) at 0.057 mW/mm2 light. In silico modeling of the experiments reproduced the experimental findings and suggested the light levels used in experiments produced excess current similar in magnitude to endogenous myofibroblast current. Fitting the model to experimental data predicted a tissue-level electrical conductance across the 3-D interface between myofibroblasts and cardiomyocytes of ~ 5 nS/cardiomyocyte, and showed how increased myofibroblast-myocyte conductance, increased myofibroblast/myocyte capacitance ratio, and increased myofibroblast current, which occur in fibrosis, can work in tandem to produce pro-arrhythmic increases in conduction and spontaneous beating.
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Affiliation(s)
- Geran M Kostecki
- Department of Biomedical Engineering, Johns Hopkins University, 720 Rutland Ave., Baltimore, MD, 21205, USA
| | - Yu Shi
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Christopher S Chen
- Biological Design Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Daniel H Reich
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Emilia Entcheva
- Department of Biomedical Engineering, George Washington University, Washington, DC, USA
| | - Leslie Tung
- Department of Biomedical Engineering, Johns Hopkins University, 720 Rutland Ave., Baltimore, MD, 21205, USA.
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Herndon C, Astley HC, Owerkowicz T, Fenton FH. Defibrillate You Later, Alligator: Q10 Scaling and Refractoriness Keeps Alligators from Fibrillation. Integr Org Biol 2021; 3:obaa047. [PMID: 33977229 PMCID: PMC8101277 DOI: 10.1093/iob/obaa047] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Effective cardiac contraction during each heartbeat relies on the coordination of an electrical wave of excitation propagating across the heart. Dynamically induced heterogeneous wave propagation may fracture and initiate reentry-based cardiac arrhythmias, during which fast-rotating electrical waves lead to repeated self-excitation that compromises cardiac function and potentially results in sudden cardiac death. Species which function effectively over a large range of heart temperatures must balance the many interacting, temperature-sensitive biochemical processes to maintain normal wave propagation at all temperatures. To investigate how these species avoid dangerous states across temperatures, we optically mapped the electrical activity across the surfaces of alligator (Alligator mississippiensis) hearts at 23°C and 38°C over a range of physiological heart rates and compare them with that of rabbits (Oryctolagus cuniculus). We find that unlike rabbits, alligators show minimal changes in wave parameters (action potential duration and conduction velocity) which complement each other to retain similar electrophysiological wavelengths across temperatures and pacing frequencies. The cardiac electrophysiology of rabbits accommodates the high heart rates necessary to sustain an active and endothermic metabolism at the cost of increased risk of cardiac arrhythmia and critical vulnerability to temperature changes, whereas that of alligators allows for effective function over a range of heart temperatures without risk of cardiac electrical arrhythmias such as fibrillation, but is restricted to low heart rates. Synopsis La contracción cardíaca efectiva durante cada latido del corazón depende de la coordinación de una onda eléctrica de excitación que se propaga a través del corazón. Heterogéidades inducidas dinámicamente por ondas de propagación pueden resultar en fracturas de las ondas e iniciar arritmias cardíacas basadas en ondas de reingreso, durante las cuales ondas espirales eléctricas de rotación rápida producen una autoexcitación repetida que afecta la función cardíaca y pude resultar en muerte súbita cardíaca. Las especies que funcionan eficazmente en una amplia gama de temperaturas cardíacas deben equilibrar los varios procesos bioquímicos que interactúan, sensibles a la temperatura para mantener la propagación normal de ondas a todas las temperaturas. Para investigar cómo estas especies evitan los estados peligrosos a través de las temperaturas, mapeamos ópticamente la actividad eléctrica a través de las superficies de los corazones de caimanes (Alligator mississippiensis) a 23°C and 38°C sobre un rango de frecuencias fisiológicas del corazón y comparamos con el de los conejos (Oryctolagus cuniculus). Encontramos que a diferencia de los conejos, los caimanes muestran cambios mínimos en los parámetros de onda (duración potencial de acción y velocidad de conducción) que se complementan entre sí para retener longitudes de onda electrofisiológicas similares a través de los rangos de temperaturas y frecuencias de ritmo. La electrofisiología cardíaca de los conejos acomoda las altas frecuencias cardíacas necesarias para mantener un metabolismo activo y endotérmico a costa de un mayor riesgo de arritmia cardíaca y vulnerabilidad crítica a los cambios de temperatura, mientras que la de los caimanes permite un funcionamiento eficaz en una serie de temperaturas cardíacas sin riesgo de arritmias eléctricas cardíacas como la fibrilación, pero está restringida a bajas frecuencias cardíacas.
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Affiliation(s)
- Conner Herndon
- School of Physics, Georgia Institute of Technology, Atlanta, GA, USA
| | - Henry C Astley
- Department of Biology, Biomimicry Research & Innovation Center, University of Akron, Akron, OH, USA
| | - Tomasz Owerkowicz
- Department of Biology, California State University, San Bernardino, CA, USA
| | - Flavio H Fenton
- School of Physics, Georgia Institute of Technology, Atlanta, GA, USA
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34
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Hussaini S, Venkatesan V, Biasci V, Romero Sepúlveda JM, Quiñonez Uribe RA, Sacconi L, Bub G, Richter C, Krinski V, Parlitz U, Majumder R, Luther S. Drift and termination of spiral waves in optogenetically modified cardiac tissue at sub-threshold illumination. eLife 2021; 10:59954. [PMID: 33502313 PMCID: PMC7840178 DOI: 10.7554/elife.59954] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 11/28/2020] [Indexed: 01/01/2023] Open
Abstract
The development of new approaches to control cardiac arrhythmias requires a deep understanding of spiral wave dynamics. Optogenetics offers new possibilities for this. Preliminary experiments show that sub-threshold illumination affects electrical wave propagation in the mouse heart. However, a systematic exploration of these effects is technically challenging. Here, we use state-of-the-art computer models to study the dynamic control of spiral waves in a two-dimensional model of the adult mouse ventricle, using stationary and non-stationary patterns of sub-threshold illumination. Our results indicate a light-intensity-dependent increase in cellular resting membrane potentials, which together with diffusive cell-cell coupling leads to the development of spatial voltage gradients over differently illuminated areas. A spiral wave drifts along the positive gradient. These gradients can be strategically applied to ensure drift-induced termination of a spiral wave, both in optogenetics and in conventional methods of electrical defibrillation.
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Affiliation(s)
- Sayedeh Hussaini
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany.,Institute for the Dynamics of Complex Systems, Goettingen University, Goettingen, Germany.,German Center for Cardiovascular Research, Partner Site Goettingen, Goettingen, Germany
| | - Vishalini Venkatesan
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany.,University Medical Center Goettingen, Clinic of Cardiology and Pneumology, Goettingen, Germany
| | - Valentina Biasci
- European Laboratory for Non-Linear Spectroscopy, Sesto Fiorentino (FI), Italy.,Division of Physiology, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | | | - Raul A Quiñonez Uribe
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany.,German Center for Cardiovascular Research, Partner Site Goettingen, Goettingen, Germany
| | - Leonardo Sacconi
- European Laboratory for Non-Linear Spectroscopy, Sesto Fiorentino (FI), Italy.,Institute for Experimental Cardiovascular Medicine, University of Freiburg, Freiburg, Germany.,National Institute of Optics, National Research Council, Florence, Italy
| | - Gil Bub
- Department of Physiology, MGill University, Montreal, Canada
| | - Claudia Richter
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany.,German Center for Cardiovascular Research, Partner Site Goettingen, Goettingen, Germany.,University Medical Center Goettingen, Clinic of Cardiology and Pneumology, Goettingen, Germany
| | - Valentin Krinski
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany.,German Center for Cardiovascular Research, Partner Site Goettingen, Goettingen, Germany.,INPHYNI, CNRS, Sophia Antipolis, Paris, France
| | - Ulrich Parlitz
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany.,Institute for the Dynamics of Complex Systems, Goettingen University, Goettingen, Germany.,German Center for Cardiovascular Research, Partner Site Goettingen, Goettingen, Germany
| | - Rupamanjari Majumder
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany.,German Center for Cardiovascular Research, Partner Site Goettingen, Goettingen, Germany
| | - Stefan Luther
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany.,Institute for the Dynamics of Complex Systems, Goettingen University, Goettingen, Germany.,German Center for Cardiovascular Research, Partner Site Goettingen, Goettingen, Germany.,University Medical Center Goettingen, Institute of Pharmacology and Toxicology, Goettingen, Germany
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35
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Martišienė I, Mačianskienė R, Benetis R, Jurevičius J. Cardiac Optical Mapping in Situ in Swine Models: A View of the Current Situation. MEDICINA-LITHUANIA 2020; 56:medicina56110620. [PMID: 33217906 PMCID: PMC7698624 DOI: 10.3390/medicina56110620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/10/2020] [Accepted: 11/16/2020] [Indexed: 11/16/2022]
Abstract
Optical mapping is recognized as a promising tool for the registration of electrical activity in the heart. Most cardiac optical mapping experiments are performed in ex vivo isolated heart models. However, the electrophysiological properties of the heart are highly influenced by the autonomic nervous system as well as humoral regulation; therefore, in vivo investigations of heart activity in large animals are definitely preferred. Furthermore, such investigations can be considered the last step before clinical application. Recently, two comprehensive studies have examined optical mapping approaches for pig hearts in situ (in vivo), likely advancing the methodological capacity to perform complex electrophysiological investigations of the heart. Both studies had the same aim, i.e., to develop high-spatiotemporal-resolution optical mapping suitable for registration of electrical activity of pig heart in situ, but the methods chosen were different. In this brief review, we analyse and compare the results of recent studies and discuss their translational potential for in situ cardiac optical mapping applications in large animals. We focus on the modes of blood circulation that are employed, the use of different voltage-sensitive dyes and their loading procedures, and ways of eliminating contraction artefacts. Finally, we evaluate the possible scenarios for optical mapping (OM) application in large animals in situ and infer which scenario is optimal.
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Affiliation(s)
- Irma Martišienė
- Institute of Cardiology, Lithuanian University of Health Sciences, LT-50161 Kaunas, Lithuania; (I.M.); (R.M.); (R.B.)
| | - Regina Mačianskienė
- Institute of Cardiology, Lithuanian University of Health Sciences, LT-50161 Kaunas, Lithuania; (I.M.); (R.M.); (R.B.)
| | - Rimantas Benetis
- Institute of Cardiology, Lithuanian University of Health Sciences, LT-50161 Kaunas, Lithuania; (I.M.); (R.M.); (R.B.)
- Department of Cardiac, Thoracic and Vascular Surgery, Hospital of Lithuanian University of Health Sciences Kauno Klinikos, Lithuanian University of Health Sciences, LT-50161 Kaunas, Lithuania
| | - Jonas Jurevičius
- Institute of Cardiology, Lithuanian University of Health Sciences, LT-50161 Kaunas, Lithuania; (I.M.); (R.M.); (R.B.)
- Correspondence:
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36
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Acker CD, Yan P, Loew LM. Recent progress in optical voltage-sensor technology and applications to cardiac research: from single cells to whole hearts. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 154:3-10. [PMID: 31474387 PMCID: PMC7048644 DOI: 10.1016/j.pbiomolbio.2019.07.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 07/16/2019] [Accepted: 07/31/2019] [Indexed: 12/25/2022]
Abstract
The first workshop on Novel Optics-based approaches for Cardiac Electrophysiology (NOtiCE) was held in Florence Italy in 2018. Here, we learned how optical approaches have shaped our basic understanding of cardiac electrophysiology and how new technologies and approaches are being developed and validated to advance the field. Several technologies are being developed that may one day allow for new clinical approaches for diagnosing cardiac disorders and possibly intervening to treat human patients. In this review, we discuss several technologies and approaches to optical voltage imaging with voltage-sensitive dyes. We highlight the development and application of fluorinated and long wavelength voltage-sensitive dyes. These optical voltage sensors have now been applied and well validated in several different assays from cultured human stem cell-derived cardiomyocytes to whole hearts in-vivo. Imaging concepts such as dual wavelength ratiometric techniques, which are crucial to maximizing the information from optical sensors by increasing the useful signal and eliminating noise and artifacts, are presented. Finally, novel voltage sensors including photoacoustic voltage-sensitive dyes, their current capabilities and potential advantages, are introduced.
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Affiliation(s)
- Corey D Acker
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, 400 Farmington Avenue, Farmington, CT, 06030, USA.
| | - Ping Yan
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, 400 Farmington Avenue, Farmington, CT, 06030, USA
| | - Leslie M Loew
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, 400 Farmington Avenue, Farmington, CT, 06030, USA
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37
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O'Shea C, Kabir SN, Holmes AP, Lei M, Fabritz L, Rajpoot K, Pavlovic D. Cardiac optical mapping - State-of-the-art and future challenges. Int J Biochem Cell Biol 2020; 126:105804. [PMID: 32681973 PMCID: PMC7456775 DOI: 10.1016/j.biocel.2020.105804] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/10/2020] [Accepted: 07/13/2020] [Indexed: 11/06/2022]
Abstract
Cardiac optical mapping is a fluorescent imaging method to study electrical behaviour and calcium handling in the heart. Optical mapping provides higher spatio-temporal resolution than electrode techniques, allowing unique insights into cardiac electrophysiology in health and disease from a variety of pre-clinical models. Both transmembrane voltage and intracellular calcium dynamics can be studied with the use of appropriate fluorescent dyes. Optical mapping has traditionally required the use of mechanical uncouplers, however computational and technical developments have lessened the requirement for these agents. Novel fluorescent dyes have been developed to optimise spectral properties, experimental timescales, biological compatibility and fluorescence output. The combination of these developments has made possible novel mapping experiments, including recent in vivo application of the technique.
Cardiac optical mapping utilises fluorescent dyes to directly image the electrical function of the heart at a high spatio-temporal resolution which far exceeds electrode techniques. It has therefore become an invaluable tool in cardiac electrophysiological research to map the propagation of heterogeneous electrical signals across the myocardium. In this review, we introduce the principles behind cardiac optical mapping and discuss some of the challenges and state of the art in the field. Key advancements discussed include newly developed fluorescent indicators, tools for the analysis of complex datasets, panoramic imaging systems and technical and computational approaches to realise optical mapping in freely beating hearts.
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Affiliation(s)
- Christopher O'Shea
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - S Nashitha Kabir
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Andrew P Holmes
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK; Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
| | - Ming Lei
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Larissa Fabritz
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK; Department Cardiology, University Hospital Birmingham, Birmingham, UK
| | - Kashif Rajpoot
- School of Computer Science, University of Birmingham, Birmingham, UK
| | - Davor Pavlovic
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK.
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38
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Lee P, Quintanilla JG, Alfonso-Almazán JM, Galán-Arriola C, Yan P, Sánchez-González J, Pérez-Castellano N, Pérez-Villacastín J, Ibañez B, Loew LM, Filgueiras-Rama D. In vivo ratiometric optical mapping enables high-resolution cardiac electrophysiology in pig models. Cardiovasc Res 2020; 115:1659-1671. [PMID: 30753358 PMCID: PMC6704389 DOI: 10.1093/cvr/cvz039] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 01/31/2019] [Accepted: 02/06/2019] [Indexed: 11/28/2022] Open
Abstract
Aims Cardiac optical mapping is the gold standard for measuring complex electrophysiology in ex vivo heart preparations. However, new methods for optical mapping in vivo have been elusive. We aimed at developing and validating an experimental method for performing in vivo cardiac optical mapping in pig models. Methods and results First, we characterized ex vivo the excitation-ratiometric properties during pacing and ventricular fibrillation (VF) of two near-infrared voltage-sensitive dyes (di-4-ANBDQBS/di-4-ANEQ(F)PTEA) optimized for imaging blood-perfused tissue (n = 7). Then, optical-fibre recordings in Langendorff-perfused hearts demonstrated that ratiometry permits the recording of optical action potentials (APs) with minimal motion artefacts during contraction (n = 7). Ratiometric optical mapping ex vivo also showed that optical AP duration (APD) and conduction velocity (CV) measurements can be accurately obtained to test drug effects. Secondly, we developed a percutaneous dye-loading protocol in vivo to perform high-resolution ratiometric optical mapping of VF dynamics (motion minimal) using a high-speed camera system positioned above the epicardial surface of the exposed heart (n = 11). During pacing (motion substantial) we recorded ratiometric optical signals and activation via a 2D fibre array in contact with the epicardial surface (n = 7). Optical APs in vivo under general anaesthesia showed significantly faster CV [120 (63–138) cm/s vs. 51 (41–64) cm/s; P = 0.032] and a statistical trend to longer APD90 [242 (217–254) ms vs. 192 (182–233) ms; P = 0.095] compared with ex vivo measurements in the contracting heart. The average rate of signal-to-noise ratio (SNR) decay of di-4-ANEQ(F)PTEA in vivo was 0.0671 ± 0.0090 min−1. However, reloading with di-4-ANEQ(F)PTEA fully recovered the initial SNR. Finally, toxicity studies (n = 12) showed that coronary dye injection did not generate systemic nor cardiac damage, although di-4-ANBDQBS injection induced transient hypotension, which was not observed with di-4-ANEQ(F)PTEA. Conclusions In vivo optical mapping using voltage ratiometry of near-infrared dyes enables high-resolution cardiac electrophysiology in translational pig models.
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Affiliation(s)
- Peter Lee
- Essel Research and Development Inc., Toronto, 337 Sheppard Ave East, Toronto, Ontario M2N 3B3, Canada
| | - Jorge G Quintanilla
- Spanish National Cardiovascular Research Center, Carlos III (CNIC), Myocardial Pathophysiology Area, Melchor Fernández Almagro, 3, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Av. Monforte de Lemos 3-5, Madrid, Spain.,Arrhythmia Unit, Cardiovascular Institute, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Prof. Martín Lagos s/n, Madrid, Spain
| | - José M Alfonso-Almazán
- Spanish National Cardiovascular Research Center, Carlos III (CNIC), Myocardial Pathophysiology Area, Melchor Fernández Almagro, 3, Madrid, Spain
| | - Carlos Galán-Arriola
- Spanish National Cardiovascular Research Center, Carlos III (CNIC), Myocardial Pathophysiology Area, Melchor Fernández Almagro, 3, Madrid, Spain
| | - Ping Yan
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, 263 Farmington Avenue, Farmington, CT, USA
| | | | - Nicasio Pérez-Castellano
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Av. Monforte de Lemos 3-5, Madrid, Spain.,Arrhythmia Unit, Cardiovascular Institute, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Prof. Martín Lagos s/n, Madrid, Spain
| | - Julián Pérez-Villacastín
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Av. Monforte de Lemos 3-5, Madrid, Spain.,Arrhythmia Unit, Cardiovascular Institute, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Prof. Martín Lagos s/n, Madrid, Spain.,Fundación Interhospitalaria para la Investigación Cardiovascular (FIC), Paseo de San Francisco de Sales 3, Madrid, Spain
| | - Borja Ibañez
- Spanish National Cardiovascular Research Center, Carlos III (CNIC), Myocardial Pathophysiology Area, Melchor Fernández Almagro, 3, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Av. Monforte de Lemos 3-5, Madrid, Spain.,IIS-University Hospital Fundación Jiménez Díaz, Department of Cardiology, Av. Reyes Católicos 2, Madrid, Spain
| | - Leslie M Loew
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, 263 Farmington Avenue, Farmington, CT, USA
| | - David Filgueiras-Rama
- Spanish National Cardiovascular Research Center, Carlos III (CNIC), Myocardial Pathophysiology Area, Melchor Fernández Almagro, 3, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Av. Monforte de Lemos 3-5, Madrid, Spain.,Arrhythmia Unit, Cardiovascular Institute, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Prof. Martín Lagos s/n, Madrid, Spain
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Abstract
High-density (HD) mapping presents opportunities to enhance delineation of atrial fibrillation (AF) substrate, improve efficiency of the mapping procedure without sacrificing safety, and afford new mechanistic insights regarding AF. Innovations in hardware, software algorithms, and development of novel multielectrode catheters have allowed HD mapping to be feasible and reliable. Patients to particularly benefit from this technology are those with paroxysmal AF in setting of preexisting atrial scar, persistent AF, and AF in the setting of complex congenital heart disease. The future will bring refinements in automated HD mapping including evolution of noncontact methodologies and artificial intelligence to supplant current techniques.
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40
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Optical mapping of the pig heart in situ under artificial blood circulation. Sci Rep 2020; 10:8548. [PMID: 32444634 PMCID: PMC7244500 DOI: 10.1038/s41598-020-65464-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 04/22/2020] [Indexed: 12/05/2022] Open
Abstract
The emergence of optical imaging has revolutionized the investigation of cardiac electrical activity and associated disorders in various cardiac pathologies. The electrical signals of the heart and the propagation pathways are crucial for elucidating the mechanisms of various cardiac pathological conditions, including arrhythmia. The synthesis of near-infrared voltage-sensitive dyes and the voltage sensitivity of the FDA-approved dye Cardiogreen have increased the importance of optical mapping (OM) as a prospective tool in clinical practice. We aimed to develop a method for the high-spatiotemporal-resolution OM of the large animal hearts in situ using di-4-ANBDQBS and Cardiogreen under patho/physiological conditions. OM was adapted to monitor cardiac electrical behaviour in an open-chest pig heart model with physiological or artificial blood circulation. We detail the methods and display the OM data obtained using di-4-ANBDQBS and Cardiogreen. Activation time, action potential duration, repolarization time and conduction velocity maps were constructed. The technique was applied to track cardiac electrical activity during regional ischaemia and arrhythmia. Our study is the first to apply high-spatiotemporal-resolution OM in the pig heart in situ to record cardiac electrical activity qualitatively under artificial blood perfusion. The use of an FDA-approved voltage-sensitive dye and artificial blood perfusion in a swine model, which is generally accepted as a valuable pre-clinical model, demonstrates the promise of OM for clinical application.
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Kurtaliev EN, Nizomov NN, Yarmukhamedov AS. Spectral-luminescent and photochemical characteristics of some styrylcyanine dyes in solutions. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2019.127395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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42
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Scardigli M, Cannazzaro S, Coppini R, Crocini C, Yan P, Loew LM, Sartiani L, Cerbai E, Pavone FS, Sacconi L, Ferrantini C. Arrhythmia susceptibility in a rat model of acute atrial dilation. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 154:21-29. [PMID: 32063273 DOI: 10.1016/j.pbiomolbio.2019.08.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 08/17/2019] [Accepted: 08/27/2019] [Indexed: 12/11/2022]
Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia, associated with an increased risk of stroke and heart failure. Acute AF occurs in response to sudden increases of atrial hemodynamic load, leading to atrial stretch. The mechanisms of stretch-induced AF were investigated in large mammals with controversial results. We optimized an approach to monitor rat atrial electrical activity using a red-shifted voltage sensitive dye (VSD). The methodology includes cauterization of the main ventricular coronary arteries, allowing improved atrial staining by the VSD and appropriate atrial perfusion for long experiments. Next, we developed a rat model of acute biatrial dilation (ABD) through the insertion of latex balloons into both atria, which could be inflated with controlled volumes. A chronic model of atrial dilation (spontaneous hypertensive rats; SHR) was used for comparison. ABD was performed on atria from healthy Wistar-Kyoto (WKY) rats (WKY-ABD). The atria were characterized in terms of arrhythmias susceptibility, action potential duration and conduction velocity. The occurrence of arrhythmias in WKY-ABD was significantly higher compared to non-dilated WKY atria. In WKY-ABD we found a reduction of conduction velocity, similar to that observed in SHR atria, while action potential duration was unchanged. Low-dose caffeine was used to introduce a drop of CV in WKY atria (WKY-caff), quantitatively similar to the one observed after ABD, but no increased arrhythmia susceptibility was observed with caffeine only. In conclusion, CV decrease is not sufficient to promote arrhythmias; enlargement of atrial surface is essential to create a substrate for acute reentry-based arrhythmias.
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Affiliation(s)
- M Scardigli
- European Laboratory for Non-Linear Spectroscopy, 50019, Sesto Fiorentino (FI), Italy
| | - S Cannazzaro
- National Institute of Optics, National Research Council, 50125, Florence, Italy
| | - R Coppini
- Division of Pharmacology, Department "NeuroFarBa,", University of Florence, 50139, Florence, Italy
| | - C Crocini
- Department of Molecular, Cellular, and Developmental Biology and BioFrontiers Institute, University of Colorado, Boulder, USA
| | - 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
| | - L Sartiani
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, CT, 06030, USA
| | - E Cerbai
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, CT, 06030, USA
| | - F S Pavone
- European Laboratory for Non-Linear Spectroscopy, 50019, Sesto Fiorentino (FI), Italy; National Institute of Optics, National Research Council, 50125, Florence, Italy; Department of Physics and Astronomy, University of Florence, 50019, Sesto Fiorentino (FI), Italy
| | - L Sacconi
- European Laboratory for Non-Linear Spectroscopy, 50019, Sesto Fiorentino (FI), Italy; National Institute of Optics, National Research Council, 50125, Florence, Italy
| | - C Ferrantini
- European Laboratory for Non-Linear Spectroscopy, 50019, Sesto Fiorentino (FI), Italy; Division of Physiology, Department of Experimental and Clinical Medicine, University of Florence, 50134, Florence, Italy.
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43
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Physiological phenotyping of the adult zebrafish heart. Mar Genomics 2020; 49:100701. [DOI: 10.1016/j.margen.2019.100701] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 08/11/2019] [Accepted: 08/13/2019] [Indexed: 12/27/2022]
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44
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Nesmith HW, Zhang H, Rogers JM. Optical mapping of electromechanics in intact organs. Exp Biol Med (Maywood) 2019; 245:368-373. [PMID: 31842618 DOI: 10.1177/1535370219894942] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Optical mapping has become a widely used and important method in cardiac electrophysiology. The method typically uses voltage-sensitive fluorescent dyes and high-speed cameras to image propagation of electrical waves. However, signals are highly susceptible to artifact caused by motion of the target organ. Consequently, cardiac optical mapping is traditionally performed in isolated, perfused organs whose contraction has been pharmacologically arrested. This has prevented optical mapping from being used to study interactions between electrical and mechanical motion. However, recently, a number of groups have developed methods to implement cardiac optical mapping in the presence of motion. These methods employ two basic strategies: (1) compensate for motion by measuring it or (2) ratiometry. In ratiometry, two signals are recorded from each site. The signals have differing sensitivity to membrane potential, but common motion artifact, which can be cancelled by taking the ratio of the two signals. Some methods use both of these strategies. Methods that measure motion have the additional advantage that this information can be used to quantify the organ’s mechanical function. Doing so enables combined “electromechanical mapping,” which allows optical study of electromechanical interactions. By allowing recording in the presence of motion, the new methods open the door to optical recording in in-vivo preparations. In addition, it is possible to implement electromechanical optical mapping techniques in organ systems other than the heart. For example, it was recently shown that optical mapping of slow wave propagation in the swine stomach is feasible. Such studies have the potential to uncover new information on the role of dysrhythmic slow wave propagation in gastric motility disorders. Impact statement Electrical and mechanical functions in the heart are bidirectionally coupled, yet are usually studied separately because of the different instrumentation technologies that are used in the two areas. Optical mapping is a powerful and widespread tool for imaging electrical propagation, but has traditionally required mechanical function to be arrested. Recently new methods have been devised that enable optical mapping to be performed in beating hearts and also to simultaneously quantify mechanical function. These new technologies promise to yield new information about electromechanical interactions in normal and pathological settings. They are also beginning to find application in other organ systems such as the gastrointestinal tract where they may provide new insight into motility disorders.
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Affiliation(s)
- Haley W Nesmith
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Hanyu Zhang
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Jack M Rogers
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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45
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Neuber JU, Varghese F, Pakhomov AG, Zemlin CW. Using Nanosecond Shocks for Cardiac Defibrillation. Bioelectricity 2019; 1:240-246. [PMID: 32685917 DOI: 10.1089/bioe.2019.0030] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The purpose of this review article is to summarize our current understanding of the efficacy and safety of cardiac defibrillation with nanosecond shocks. Experiments in isolated hearts, using optical mapping of the electrical activity, have demonstrated that nanosecond shocks can defibrillate with lower energies than conventional millisecond shocks. Single defibrillation strength nanosecond shocks do not cause obvious damage, but repeated stimulation leads to deterioration of the hearts. In isolated myocytes, nanosecond pulses can also stimulate at lower energies than at longer pulses and cause less electroporation (propidium uptake). The mechanism is likely electroporation of the plasma membrane. Repeated stimulation leads to distorted calcium gradients.
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Affiliation(s)
- Johanna U Neuber
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia.,Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia
| | - Frency Varghese
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia
| | - Christian W Zemlin
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia.,Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia
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46
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Zgierski-Johnston CM, Ayub S, Fernández MC, Rog-Zielinska EA, Barz F, Paul O, Kohl P, Ruther P. Cardiac pacing using transmural multi-LED probes in channelrhodopsin-expressing mouse hearts. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 154:51-61. [PMID: 31738979 PMCID: PMC7322525 DOI: 10.1016/j.pbiomolbio.2019.11.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 10/07/2019] [Accepted: 11/13/2019] [Indexed: 02/03/2023]
Abstract
Optogenetics enables cell-type specific monitoring and actuation via light-activated proteins. In cardiac research, expressing light-activated depolarising ion channels in cardiomyocytes allows optical pacing and defibrillation. Previous studies largely relied on epicardial illumination. Light penetration through the myocardium is however problematic when moving to larger animals and humans. To overcome this limitation, we assessed the utility of an implantable multi light-emitting diode (LED) optical probe (IMLOP) for intramural pacing of mouse hearts expressing cardiac-specific channelrhodopsin-2 (ChR2). Here we demonstrated that IMLOP insertion needs approximately 20 mN of force, limiting possible damage from excessive loads applied during implantation. Histological sections confirmed the confined nature of tissue damage during acute use. The temperature change of the surrounding tissue was below 1 K during LED operation, rendering the probe safe for use in situ. This was confirmed in control experiments where no effect on cardiac action potential conduction was observed even when using stimulation parameters twenty-fold greater than required for pacing. In situ experiments on ChR2-expressing mouse hearts demonstrated that optical stimulation is possible with light intensities as low as 700 μW/mm2; although stable pacing requires higher intensities. When pacing with a single LED, rheobase and chronaxie values were 13.3 mW/mm2 ± 0.9 mW/mm2 and 3 ms ± 0.6 ms, respectively. When doubling the stimulated volume the rheobase decreased significantly (6.5 mW/mm2 ± 0.9 mW/mm2). We have demonstrated IMLOP-based intramural optical pacing of the heart. Probes cause locally constrained tissue damage in the acute setting and require low light intensities for pacing. Further development is necessary to assess effects of chronic implantation.
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Affiliation(s)
- C M Zgierski-Johnston
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, Medical Center, University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany.
| | - S Ayub
- Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany
| | - M C Fernández
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, Medical Center, University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - E A Rog-Zielinska
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, Medical Center, University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - F Barz
- Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany
| | - O Paul
- Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany; Cluster of Excellence BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
| | - P Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, Medical Center, University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - P Ruther
- Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany; Cluster of Excellence BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
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47
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Jaimes R, McCullough D, Siegel B, Swift L, Hiebert J, Mclnerney D, Posnack NG. Lights, camera, path splitter: a new approach for truly simultaneous dual optical mapping of the heart with a single camera. BMC Biomed Eng 2019; 1. [PMID: 31768502 PMCID: PMC6876868 DOI: 10.1186/s42490-019-0024-x] [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] [Indexed: 01/18/2023] Open
Abstract
Background Optical mapping of transmembrane voltage and intracellular calcium is a powerful tool for investigating cardiac physiology and pathophysiology. However, simultaneous dual mapping of two fluorescent probes remains technically challenging. We introduce a novel, easy-to-use approach that requires a path splitter, single camera and excitation light to simultaneously acquire voltage and calcium signals from whole heart preparations, which can be applied to other physiological models – including neurons and isolated cardiomyocytes. Results Complementary probes were selected that could be excited with a single wavelength light source. Langendorff-perfused hearts (rat, swine) were stained and imaged using a sCMOS camera outfitted with an optical path splitter to simultaneously acquire two emission fields at high spatial and temporal resolution. Voltage (RH237) and calcium (Rhod2) signals were acquired concurrently on a single sensor, resulting in two 384 × 256 images at 814 frames per second. At this frame rate, the signal-to-noise ratio was 47 (RH237) and 85 (Rhod2). Imaging experiments were performed on small rodent hearts, as well as larger pig hearts with sufficient optical signals. In separate experiments, each dye was used independently to assess crosstalk and demonstrate signal specificity. Additionally, the effect of ryanodine on myocardial calcium transients was validated – with no measurable effect on the amplitude of optical action potentials. To demonstrate spatial resolution, ventricular tachycardia was induced –resulting in the novel finding that spatially discordant calcium alternans can be present in different regions of the heart, even when electrical alternans remain concordant. The described system excels in providing a wide field of view and high spatiotemporal resolution for a variety of cardiac preparations. Conclusions We report the first multiparametric mapping system that simultaneously acquires calcium and voltage signals from cardiac preparations, using a path splitter, single camera and excitation light. This approach eliminates the need for multiple cameras, excitation light patterning or frame interleaving. These features can aid in the adoption of dual mapping technology by the broader cardiovascular research community, and decrease the barrier of entry into panoramic heart imaging, as it reduces the number of required cameras. Electronic supplementary material The online version of this article (10.1186/s42490-019-0024-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rafael Jaimes
- Sheikh Zayed Institute for Pediatric and Surgical Innovation: Children's National Health System, 6th floor, M7708, 111 Michigan Avenue NW, Washington, DC 20010, USA.,Children's National Heart Institute: Children's National Health System, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Damon McCullough
- Sheikh Zayed Institute for Pediatric and Surgical Innovation: Children's National Health System, 6th floor, M7708, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Bryan Siegel
- Children's National Heart Institute: Children's National Health System, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Luther Swift
- Sheikh Zayed Institute for Pediatric and Surgical Innovation: Children's National Health System, 6th floor, M7708, 111 Michigan Avenue NW, Washington, DC 20010, USA.,Children's National Heart Institute: Children's National Health System, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - James Hiebert
- Sheikh Zayed Institute for Pediatric and Surgical Innovation: Children's National Health System, 6th floor, M7708, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Daniel Mclnerney
- Sheikh Zayed Institute for Pediatric and Surgical Innovation: Children's National Health System, 6th floor, M7708, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Nikki Gillum Posnack
- Sheikh Zayed Institute for Pediatric and Surgical Innovation: Children's National Health System, 6th floor, M7708, 111 Michigan Avenue NW, Washington, DC 20010, USA.,Children's National Heart Institute: Children's National Health System, 111 Michigan Avenue NW, Washington, DC 20010, USA.,Department of Pediatrics, Department of Pharmacology & Physiology, School of Medicine and Health Sciences: George Washington University, 2300 I Street NW, Washington, DC 20037, USA
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48
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Wang L, Ripplinger CM. Putting the pieces together using in vivo optical mapping. Cardiovasc Res 2019; 115:1574-1575. [PMID: 30924872 DOI: 10.1093/cvr/cvz089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Lianguo Wang
- Department of Pharmacology, UC Davis School of Medicine, 2419B Tupper Hall, One Shields Ave, Davis, CA 95616, USA
| | - Crystal M Ripplinger
- Department of Pharmacology, UC Davis School of Medicine, 2419B Tupper Hall, One Shields Ave, Davis, CA 95616, USA
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49
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Uzelac I, Iravanian S, Fenton FH. Parallel Acceleration on Removal of Optical Mapping Baseline Wandering. COMPUTING IN CARDIOLOGY 2019; 46:10.22489/cinc.2019.433. [PMID: 35719209 PMCID: PMC9202644 DOI: 10.22489/cinc.2019.433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Optical mapping measurements on hearts stained with fluorescent dyes is imagining method widely accepted and recognized as a tool to study complex spatial-temporal dynamics of cardiac electro-physiology. One shortcoming of the method is baseline wandering in obtained fluorescence signals as signals relevant to transmembrane potential (Vm) change and free intracellular calcium concentration ([Ca]i +2), the two most used dyes, are calculated as a relative signal change in respect to the fluorescence baseline. These changes are small fractional changes often smaller than 10 %. Baseline fluorescence drifts due to dye photo-bleaching, heart contraction/movement artifacts, and stability of the excitation light source over time. Depending on experimental instrumentation, recording duration, signal to noise levels and study aims of the optical imagining, many research groups adopted their own techniques tailored to a specific experimental data. Here we present a technique based on finite impulse response (FIR) filters with paralleled acceleration implemented on GPUs and multi-core CPU, in MATLAB.
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Affiliation(s)
- Ilija Uzelac
- School of Physics, Georgia Intitute of Technology, Atlanta, GA, USA
| | | | - Flavio H Fenton
- School of Physics, Georgia Intitute of Technology, Atlanta, GA, USA
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50
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Ayub S, Ruther P, Paul O, Kohl P, Zgierski-Johnston CM. Invasive Optical Pacing in Perfused, Optogenetically Modified Mouse Heart Using Stiff Multi-LED Optical Probes. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2019; 2018:1-4. [PMID: 30440302 DOI: 10.1109/embc.2018.8513166] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We present the first invasive use of a stiff, multiLED optical probe for intramural optical stimulation of cardiac tissue. We demonstrate that optical pacing is possible with high spatial and temporal resolution in transgenic mice expressing channelrhodopsin-2. The technical implementation of this study builds on optical probes recently developed and tested ex vivo in cerebral tissue of mice. The probes comprise LEDs integrated on flexible substrates stiffened by silicon-based MEMS structures enabling the successful penetration into the cardiac tissue. The probe technology is extended to allow dual-sided illumination for directional tissue stimulation. Implantation trials affirm the ability to optically pace the isolated perfused heart at stimulation frequencies between 4Hz and 12Hz with experimentally determined emittance levels of 10mW mm-2 Rapid activation of two distant LEDs could reliably be used to induce short runs of ventricular fibrillation, while simultaneous activation of all LEDs allowed termination of re-entrant rhythm disturbances (optical defibrillation). Thus, spatially-resolved intramural pacing and rhythm control of the isolated heart is possible using stiff, multi-LED optical probes.
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