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Zhao Y, Du B, Chakraborty P, Denham N, Massé S, Lai PF, Azam MA, Billia F, Thavendiranathan P, Abdel‐Qadir H, Lopaschuk GD, Nanthakumar K. Impaired Cardiac AMPK (5'-Adenosine Monophosphate-Activated Protein Kinase) and Ca 2+-Handling, and Action Potential Duration Heterogeneity in Ibrutinib-Induced Ventricular Arrhythmia Vulnerability. J Am Heart Assoc 2024; 13:e032357. [PMID: 38842296 PMCID: PMC11255774 DOI: 10.1161/jaha.123.032357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 04/03/2024] [Indexed: 06/07/2024]
Abstract
BACKGROUND We recently demonstrated that acute administration of ibrutinib, a Bruton's tyrosine kinase inhibitor used in chemotherapy for blood malignancies, increases ventricular arrhythmia (VA) vulnerability. A pathway of ibrutinib-induced vulnerability to VA that can be modulated for cardioprotection remains unclear. METHODS AND RESULTS The effects of ibrutinib on cardiac electrical activity and Ca2+ dynamics were investigated in Langendorff-perfused hearts using optical mapping. We also conducted Western blotting analysis to evaluate the impact of ibrutinib on various regulatory and Ca2+-handling proteins in rat cardiac tissues. Treatment with ibrutinib (10 mg/kg per day) for 4 weeks was associated with an increased VA inducibility (72.2%±6.3% versus 38.9±7.0% in controls, P<0.002) and shorter action potential durations during pacing at various frequencies (P<0.05). Ibrutinib also decreased heart rate thresholds for beat-to-beat duration alternans of the cardiac action potential (P<0.05). Significant changes in myocardial Ca2+ transients included lower amplitude alternans ratios (P<0.05), longer times-to-peak (P<0.05), and greater spontaneous intracellular Ca2+ elevations (P<0.01). We also found lower abundance and phosphorylation of myocardial AMPK (5'-adenosine monophosphate-activated protein kinase), indicating reduced AMPK activity in hearts after ibrutinib treatment. An acute treatment with the AMPK activator 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside ameliorated abnormalities in action potential and Ca2+ dynamics, and significantly reduced VA inducibility (37.1%±13.4% versus 72.2%±6.3% in the absence of 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside, P<0.05) in hearts from ibrutinib-treated rats. CONCLUSIONS VA vulnerability inflicted by ibrutinib may be mediated in part by an impairment of myocardial AMPK activity. Pharmacological activation of AMPK may be a protective strategy against ibrutinib-induced cardiotoxicity.
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MESH Headings
- Animals
- Adenine/analogs & derivatives
- Adenine/pharmacology
- Piperidines/pharmacology
- Action Potentials/drug effects
- Pyrimidines/pharmacology
- AMP-Activated Protein Kinases/metabolism
- Pyrazoles/pharmacology
- Male
- Arrhythmias, Cardiac/chemically induced
- Arrhythmias, Cardiac/metabolism
- Arrhythmias, Cardiac/physiopathology
- Arrhythmias, Cardiac/prevention & control
- Protein Kinase Inhibitors/pharmacology
- Heart Rate/drug effects
- Isolated Heart Preparation
- Calcium/metabolism
- Rats
- Disease Models, Animal
- Rats, Sprague-Dawley
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/enzymology
- Myocytes, Cardiac/pathology
- Calcium Signaling/drug effects
- Time Factors
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Affiliation(s)
- Yanan Zhao
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General HospitalTorontoCanada
- Toronto General Hospital Research InstituteTorontoCanada
- China‐Japan Union Hospital of Jilin UniversityChangchunChina
| | - Beibei Du
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General HospitalTorontoCanada
- Toronto General Hospital Research InstituteTorontoCanada
- China‐Japan Union Hospital of Jilin UniversityChangchunChina
| | - Praloy Chakraborty
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General HospitalTorontoCanada
- Toronto General Hospital Research InstituteTorontoCanada
| | - Nathan Denham
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General HospitalTorontoCanada
- Toronto General Hospital Research InstituteTorontoCanada
| | - Stéphane Massé
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General HospitalTorontoCanada
- Toronto General Hospital Research InstituteTorontoCanada
| | - Patrick F.H. Lai
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General HospitalTorontoCanada
- Toronto General Hospital Research InstituteTorontoCanada
| | - Mohammed Ali Azam
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General HospitalTorontoCanada
- Toronto General Hospital Research InstituteTorontoCanada
| | - Filio Billia
- Toronto General Hospital Research InstituteTorontoCanada
- Ted Rogers Centre for Heart ResearchTorontoCanada
| | | | - Husam Abdel‐Qadir
- Toronto General Hospital Research InstituteTorontoCanada
- Ted Rogers Centre for Heart ResearchTorontoCanada
| | | | - Kumaraswamy Nanthakumar
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General HospitalTorontoCanada
- Toronto General Hospital Research InstituteTorontoCanada
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2
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Zhao Y, Chakraborty P, Tomassetti J, Subha T, Massé S, Thavendiranathan P, Billia F, Lai PFH, Abdel-Qadir H, Nanthakumar K. Arrhythmogenic Ventricular Remodeling by Next-Generation Bruton's Tyrosine Kinase Inhibitor Acalabrutinib. Int J Mol Sci 2024; 25:6207. [PMID: 38892396 PMCID: PMC11173147 DOI: 10.3390/ijms25116207] [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: 04/20/2024] [Revised: 05/22/2024] [Accepted: 05/24/2024] [Indexed: 06/21/2024] Open
Abstract
Cardiac arrhythmias remain a significant concern with Ibrutinib (IBR), a first-generation Bruton's tyrosine kinase inhibitor (BTKi). Acalabrutinib (ABR), a next-generation BTKi, is associated with reduced atrial arrhythmia events. However, the role of ABR in ventricular arrhythmia (VA) has not been adequately evaluated. Our study aimed to investigate VA vulnerability and ventricular electrophysiology following chronic ABR therapy in male Sprague-Dawley rats utilizing epicardial optical mapping for ventricular voltage and Ca2+ dynamics and VA induction by electrical stimulation in ex-vivo perfused hearts. Ventricular tissues were snap-frozen for protein analysis for sarcoplasmic Ca2+ and metabolic regulatory proteins. The results show that both ABR and IBR treatments increased VA vulnerability, with ABR showing higher VA regularity index (RI). IBR, but not ABR, is associated with the abbreviation of action potential duration (APD) and APD alternans. Both IBR and ABR increased diastolic Ca2+ leak and Ca2+ alternans, reduced conduction velocity (CV), and increased CV dispersion. Decreased SERCA2a expression and AMPK phosphorylation were observed with both treatments. Our results suggest that ABR treatment also increases the risk of VA by inducing proarrhythmic changes in Ca2+ signaling and membrane electrophysiology, as seen with IBR. However, the different impacts of these two BTKi on ventricular electrophysiology may contribute to differences in VA vulnerability and distinct VA characteristics.
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Affiliation(s)
- Yanan Zhao
- Toronto General Hospital Research Institute, University Health Network, Toronto, ON M5G 2M1, Canada; (Y.Z.); (P.C.); (J.T.); (T.S.); (S.M.); (P.T.); (F.B.); (P.F.H.L.); (H.A.-Q.)
| | - Praloy Chakraborty
- Toronto General Hospital Research Institute, University Health Network, Toronto, ON M5G 2M1, Canada; (Y.Z.); (P.C.); (J.T.); (T.S.); (S.M.); (P.T.); (F.B.); (P.F.H.L.); (H.A.-Q.)
| | - Julianna Tomassetti
- Toronto General Hospital Research Institute, University Health Network, Toronto, ON M5G 2M1, Canada; (Y.Z.); (P.C.); (J.T.); (T.S.); (S.M.); (P.T.); (F.B.); (P.F.H.L.); (H.A.-Q.)
| | - Tasnia Subha
- Toronto General Hospital Research Institute, University Health Network, Toronto, ON M5G 2M1, Canada; (Y.Z.); (P.C.); (J.T.); (T.S.); (S.M.); (P.T.); (F.B.); (P.F.H.L.); (H.A.-Q.)
| | - Stéphane Massé
- Toronto General Hospital Research Institute, University Health Network, Toronto, ON M5G 2M1, Canada; (Y.Z.); (P.C.); (J.T.); (T.S.); (S.M.); (P.T.); (F.B.); (P.F.H.L.); (H.A.-Q.)
| | - Paaladinesh Thavendiranathan
- Toronto General Hospital Research Institute, University Health Network, Toronto, ON M5G 2M1, Canada; (Y.Z.); (P.C.); (J.T.); (T.S.); (S.M.); (P.T.); (F.B.); (P.F.H.L.); (H.A.-Q.)
- Ted Rogers Centre for Heart Research, Toronto, ON M5G 1M1, Canada
| | - Filio Billia
- Toronto General Hospital Research Institute, University Health Network, Toronto, ON M5G 2M1, Canada; (Y.Z.); (P.C.); (J.T.); (T.S.); (S.M.); (P.T.); (F.B.); (P.F.H.L.); (H.A.-Q.)
- Ted Rogers Centre for Heart Research, Toronto, ON M5G 1M1, Canada
| | - Patrick F. H. Lai
- Toronto General Hospital Research Institute, University Health Network, Toronto, ON M5G 2M1, Canada; (Y.Z.); (P.C.); (J.T.); (T.S.); (S.M.); (P.T.); (F.B.); (P.F.H.L.); (H.A.-Q.)
| | - Husam Abdel-Qadir
- Toronto General Hospital Research Institute, University Health Network, Toronto, ON M5G 2M1, Canada; (Y.Z.); (P.C.); (J.T.); (T.S.); (S.M.); (P.T.); (F.B.); (P.F.H.L.); (H.A.-Q.)
- Ted Rogers Centre for Heart Research, Toronto, ON M5G 1M1, Canada
- Women’s College Hospital, Toronto, ON M5S 1B2, Canada
| | - Kumaraswamy Nanthakumar
- Toronto General Hospital Research Institute, University Health Network, Toronto, ON M5G 2M1, Canada; (Y.Z.); (P.C.); (J.T.); (T.S.); (S.M.); (P.T.); (F.B.); (P.F.H.L.); (H.A.-Q.)
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3
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Cooper BL, Salameh S, Posnack NG. Comparative cardiotoxicity assessment of bisphenol chemicals and estradiol using human induced pluripotent stem cell-derived cardiomyocytes. Toxicol Sci 2024; 198:273-287. [PMID: 38310357 PMCID: PMC10964748 DOI: 10.1093/toxsci/kfae015] [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] [Indexed: 02/05/2024] Open
Abstract
Bisphenol A (BPA) is commonly used to manufacture consumer and medical-grade plastics. Due to health concerns, BPA substitutes are being incorporated-including bisphenol S (BPS) and bisphenol F (BPF)-without a comprehensive understanding of their toxicological profile. Previous studies suggest that bisphenol chemicals perturb cardiac electrophysiology in a manner that is similar to 17β-estradiol (E2). We aimed to compare the effects of E2 with BPA, BPF, and BPS using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). Cardiac parameters were evaluated using microelectrode array (MEA) technology and live-cell fluorescent imaging. Cardiac metrics remained relatively stable after exposure to nanomolar concentrations (1-1000 nM) of E2, BPA, BPF, or BPS. At higher micromolar concentrations, chemical exposures decreased the depolarization spike amplitude, and shortened the field potential, action potential duration, and calcium transient duration (E2 ≥ BPA ≥ BPF ≫ BPS). Cardiomyocyte physiology was largely undisturbed by BPS. BPA-induced effects were exaggerated when coadministered with an L-type calcium channel (LTCC) antagonist or E2, and reduced when coadministered with an LTCC agonist or an estrogen receptor alpha antagonist. E2-induced effects were not exaggerated by coadministration with an LTCC antagonist. Although the observed cardiac effects of E2 and BPA were similar, a few distinct differences suggest that these chemicals may act (in part) through different mechanisms. hiPSC-CM are a useful model for screening cardiotoxic chemicals, nevertheless, the described findings should be validated using a more complex ex vivo and/or in vivo model.
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Affiliation(s)
- Blake L Cooper
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, Washington, District of Columbia 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, District of Columbia 20010, USA
- Department of Pharmacology & Physiology, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia 20052, USA
| | - Shatha Salameh
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, Washington, District of Columbia 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, District of Columbia 20010, USA
- Department of Pharmacology & Physiology, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia 20052, USA
| | - Nikki Gillum Posnack
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, Washington, District of Columbia 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, District of Columbia 20010, USA
- Department of Pharmacology & Physiology, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia 20052, USA
- Department of Pediatrics, School of Medicine & Health Sciences, The George Washington University, Washington, District of Columbia 20052, USA
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4
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Sun Z, Lu K, Kamla C, Kameritsch P, Seidel T, Dendorfer A. Synchronous force and Ca 2+ measurements for repeated characterization of excitation-contraction coupling in human myocardium. Commun Biol 2024; 7:220. [PMID: 38388802 PMCID: PMC10884022 DOI: 10.1038/s42003-024-05886-3] [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: 09/04/2023] [Accepted: 02/02/2024] [Indexed: 02/24/2024] Open
Abstract
Dysfunctional Ca2+ signaling affects the myocardial systole and diastole, may trigger arrhythmia and cause transcriptomic and proteomic modifications in heart failure. Thus, synchronous real-time measurement of Ca2+ and force is essential to investigate the relationship between contractility and Ca2+ signaling and the alteration of excitation-contraction coupling (ECC) in human failing myocardium. Here, we present a method for synchronized acquisition of intracellular Ca2+ and contraction force in long-term cultivated slices of human failing myocardium. Synchronous time series of contraction force and intracellular Ca2+ were used to calculate force-calcium loops and to analyze the dynamic alterations of ECC in response to various pacing frequencies, post-pause potentiation, high mechanical preload and pharmacological interventions in human failing myocardium. We provide an approach to simultaneously and repeatedly investigate alterations of contractility and Ca2+ signals in long-term cultured myocardium, which will allow detecting the effects of electrophysiological or pharmacological interventions on human myocardial ECC.
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Affiliation(s)
- Zhengwu Sun
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Kun Lu
- Department of Cardiac Surgery, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
- DZHK (German Center for Cardiovascular Research), Partner site Munich Heart Alliance, Munich, Germany
| | - Christine Kamla
- Department of Cardiac Surgery, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Petra Kameritsch
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Thomas Seidel
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Andreas Dendorfer
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany.
- DZHK (German Center for Cardiovascular Research), Partner site Munich Heart Alliance, Munich, Germany.
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5
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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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6
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Swift LM, Roberts A, Pressman J, Guerrelli D, Allen S, Haq KT, Reisz JA, D’Alessandro A, Posnack NG. Evidence for the cardiodepressive effects of the plasticizer di-2-ethylhexyl phthalate. Toxicol Sci 2023; 197:79-94. [PMID: 37812252 PMCID: PMC10734602 DOI: 10.1093/toxsci/kfad105] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2023] Open
Abstract
Di-2-ethylhexyl phthalate (DEHP) is commonly used in the manufacturing of plastic materials, including intravenous bags, blood storage bags, and medical-grade tubing. DEHP can leach from plastic medical products, which can result in inadvertent patient exposure. DEHP concentrations were measured in red blood cell units stored between 7 and 42 days (17-119 μg/ml). Using these concentrations as a guide, Langendorff-perfused rat heart preparations were acutely exposed to DEHP. Sinus activity remained stable with lower doses of DEHP (25-50 μg/ml), but sinus rate declined by 43% and sinus node recovery time (SNRT) prolonged by 56.5% following 30-min exposure to 100 μg/ml DEHP. DEHP exposure also exerted a negative dromotropic response, as indicated by a 69.4% longer PR interval, 108.5% longer Wenckebach cycle length (WBCL), and increased incidence of atrioventricular (AV) uncoupling (60-min exposure). Pretreatment with doxycycline partially rescued the effects of DEHP on sinus activity, but did not ameliorate the effects on AV conduction. DEHP exposure also prolonged the ventricular action potential and effective refractory period, but had no measurable effect on intracellular calcium transient duration. Follow-up studies using human-induced pluripotent stem cell-derived cardiomyocytes confirmed that DEHP slows electrical conduction in a time (15 min-3 h) and dose-dependent manner (10-100 μg/ml). Previous studies have suggested that phthalate toxicity is specifically attributed to metabolites of DEHP, including mono-2-ethylhexylphthalate. This study demonstrates that DEHP exposure also contributes to cardiac dysfunction in a dose- and time-dependent manner. Future work is warranted to investigate the impact of DEHP (and its metabolites) on human health, with special consideration for clinical procedures that employ plastic materials.
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Affiliation(s)
- Luther M Swift
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, Washington, District of Columbia 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, District of Columbia 20010, USA
| | - Anysja Roberts
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, Washington, District of Columbia 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, District of Columbia 20010, USA
| | - Jenna Pressman
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, Washington, District of Columbia 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, District of Columbia 20010, USA
- Department of Biomedical Engineering, School of Engineering and Applied Sciences, The George Washington University, Washington, District of Columbia 20037, USA
| | - Devon Guerrelli
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, Washington, District of Columbia 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, District of Columbia 20010, USA
- Department of Biomedical Engineering, School of Engineering and Applied Sciences, The George Washington University, Washington, District of Columbia 20037, USA
| | - Samuel Allen
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, Washington, District of Columbia 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, District of Columbia 20010, USA
| | - Kazi T Haq
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, Washington, District of Columbia 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, District of Columbia 20010, USA
| | - Julie A Reisz
- Department of Biochemistry and Molecular Genetics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Angelo D’Alessandro
- Department of Biochemistry and Molecular Genetics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Nikki Gillum Posnack
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, Washington, District of Columbia 20010, USA
- Children’s National Heart Institute, Children’s National Hospital, Washington, District of Columbia 20010, USA
- Department of Pediatrics, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia 20037, USA
- Department of Pharmacology & Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia 20037, USA
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7
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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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8
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Cooper BL, Salameh S, Posnack NG. Comparative cardiotoxicity assessment of bisphenol chemicals and estradiol using human induced pluripotent stem cell-derived cardiomyocytes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.13.557564. [PMID: 37745451 PMCID: PMC10515916 DOI: 10.1101/2023.09.13.557564] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Background Bisphenol A (BPA) is commonly used to manufacture consumer and medical-grade plastics. Due to health concerns, BPA substitutes are being incorporated - including bisphenol S (BPS) and bisphenol F (BPF) - without a comprehensive understanding of their toxicological profile. Objective Previous studies suggest that bisphenol chemicals perturb cardiac electrophysiology in a manner that is similar to 17β-estradiol (E2). We aimed to compare the effects of E2 with BPA, BPF, and BPS using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). Methods Cardiac parameters were evaluated using microelectrode array (MEA) technology and live-cell fluorescent imaging at baseline and in response to chemical exposure (0.001-100 μM). Results Cardiac metrics remained relatively stable after exposure to nanomolar concentrations (1-1,000 nM) of E2, BPA, BPF, or BPS. At higher micromolar concentrations, chemical exposures resulted in a decrease in the depolarizing spike amplitude, shorter field potential and action potential duration, shorter calcium transient duration, and decrease in hiPSC-CM contractility (E2 > BPA > BPF >> BPS). Cardiomyocyte physiology was largely undisturbed by BPS exposure. BPA-induced effects were exaggerated when co-administered with an L-type calcium channel antagonist (verapamil) or E2 - and reduced when co-administered with an L-type calcium channel agonist (Bay K8644) or an estrogen receptor alpha antagonist (MPP). E2-induced effects generally mirrored those of BPA, but were not exaggerated by co-administration with an L-type calcium channel antagonist. Discussion Collectively across multiple cardiac endpoints, E2 was the most potent and BPS was the least potent disruptor of hiPSC-CM function. Although the observed cardiac effects of E2 and BPA were similar, a few distinct differences suggest that these chemicals may act (in part) through different mechanisms. hiPSC-CM are a useful model for screening cardiotoxic chemicals, nevertheless, the described in vitro findings should be validated using a more complex ex vivo and/or in vivo model.
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Swift LM, Roberts A, Pressman J, Guerrelli D, Allen S, Haq KT, Reisz JA, D'Alessandro A, Posnack NG. Evidence for the cardiodepressive effects of the plasticizer di-2-ethylhexylphthalate (DEHP). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.22.541729. [PMID: 37293060 PMCID: PMC10245927 DOI: 10.1101/2023.05.22.541729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Di-2-ethylhexylphthalate (DEHP) is commonly used in the manufacturing of plastic materials, including intravenous bags, blood storage bags, and medical-grade tubing. DEHP can leach from plastic medical products, which can result in inadvertent patient exposure. DEHP concentrations were measured in red blood cell (RBC) units stored between 7-42 days (23-119 μg/mL). Using these concentrations as a guide, Langendorff-perfused rat heart preparations were acutely exposed to DEHP. Sinus activity remained stable with lower doses of DEHP (25-50 μg/mL), but sinus rate declined by 43% and sinus node recovery time prolonged by 56.5% following 30-minute exposure to 100 μg/ml DEHP. DEHP exposure also exerted a negative dromotropic response, as indicated by a 69.4% longer PR interval, 108.5% longer Wenckebach cycle length, and increased incidence of atrioventricular uncoupling. Pretreatment with doxycycline partially rescued the effects of DEHP on sinus activity, but did not ameliorate the effects on atrioventricular conduction. DEHP exposure also prolonged the ventricular action potential and effective refractory period, but had no measurable effect on intracellular calcium transient duration. Follow-up studies using hiPSC-CM confirmed that DEHP slows electrical conduction in a time (15 min - 3 hours) and dose-dependent manner (10-100 μg/mL). Previous studies have suggested that phthalate toxicity is specifically attributed to metabolites of DEHP, including mono-2-ethylhexyl phthalate (MEHP). This study demonstrates that DEHP exposure also contributes to cardiac dysfunction in a dose- and time-dependent manner. Future work is warranted to investigate the impact of DEHP (and its metabolites) on human health, with special consideration for clinical procedures that employ plastic materials.
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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: 3] [Impact Index Per Article: 3.0] [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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Djemai M, Cupelli M, Boutjdir M, Chahine M. Optical Mapping of Cardiomyocytes in Monolayer Derived from Induced Pluripotent Stem Cells. Cells 2023; 12:2168. [PMID: 37681899 PMCID: PMC10487143 DOI: 10.3390/cells12172168] [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: 07/18/2023] [Revised: 08/21/2023] [Accepted: 08/25/2023] [Indexed: 09/09/2023] Open
Abstract
Optical mapping is a powerful imaging technique widely adopted to measure membrane potential changes and intracellular Ca2+ variations in excitable tissues using voltage-sensitive dyes and Ca2+ indicators, respectively. This powerful tool has rapidly become indispensable in the field of cardiac electrophysiology for studying depolarization wave propagation, estimating the conduction velocity of electrical impulses, and measuring Ca2+ dynamics in cardiac cells and tissues. In addition, mapping these electrophysiological parameters is important for understanding cardiac arrhythmia mechanisms. In this review, we delve into the fundamentals of cardiac optical mapping technology and its applications when applied to hiPSC-derived cardiomyocytes and discuss related advantages and challenges. We also provide a detailed description of the processing and analysis of optical mapping data, which is a crucial step in the study of cardiac diseases and arrhythmia mechanisms for extracting and comparing relevant electrophysiological parameters.
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Affiliation(s)
- Mohammed Djemai
- CERVO Brain Research Center, Institut Universitaire en Santé Mentale de Québec, Quebec City, QC G1J 2G3, Canada
| | - Michael Cupelli
- Cardiovascular Research Program, VA New York Harbor Healthcare System, New York, NY 11209, USA
- Department of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Health Sciences University, New York, NY 11203, USA
| | - Mohamed Boutjdir
- Cardiovascular Research Program, VA New York Harbor Healthcare System, New York, NY 11209, USA
- Department of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Health Sciences University, New York, NY 11203, USA
- Department of Medicine, NYU School of Medicine, New York, NY 10016, USA
| | - Mohamed Chahine
- CERVO Brain Research Center, Institut Universitaire en Santé Mentale de Québec, Quebec City, QC G1J 2G3, Canada
- Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, QC G1V 0A6, Canada
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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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Liu S, Kumari S, He H, Mishra P, Singh BN, Singh D, Liu S, Srivastava P, Li C. Biosensors integrated 3D organoid/organ-on-a-chip system: A real-time biomechanical, biophysical, and biochemical monitoring and characterization. Biosens Bioelectron 2023; 231:115285. [PMID: 37058958 DOI: 10.1016/j.bios.2023.115285] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 03/25/2023] [Accepted: 03/28/2023] [Indexed: 04/16/2023]
Abstract
As a full-fidelity simulation of human cells, tissues, organs, and even systems at the microscopic scale, Organ-on-a-Chip (OOC) has significant ethical advantages and development potential compared to animal experiments. The need for the design of new drug high-throughput screening platforms and the mechanistic study of human tissues/organs under pathological conditions, the evolving advances in 3D cell biology and engineering, etc., have promoted the updating of technologies in this field, such as the iteration of chip materials and 3D printing, which in turn facilitate the connection of complex multi-organs-on-chips for simulation and the further development of technology-composite new drug high-throughput screening platforms. As the most critical part of organ-on-a-chip design and practical application, verifying the success of organ model modeling, i.e., evaluating various biochemical and physical parameters in OOC devices, is crucial. Therefore, this paper provides a logical and comprehensive review and discussion of the advances in organ-on-a-chip detection and evaluation technologies from a broad perspective, covering the directions of tissue engineering scaffolds, microenvironment, single/multi-organ function, and stimulus-based evaluation, and provides a more comprehensive review of the progress in the significant organ-on-a-chip research areas in the physiological state.
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Affiliation(s)
- Shan Liu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Medical Genetics, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China
| | - Shikha Kumari
- School of Biochemical Engineering, IIT BHU, Varanasi, Uttar Pradesh, India
| | - Hongyi He
- West China School of Medicine & West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Parichita Mishra
- Department of Ageing Research, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India
| | - Bhisham Narayan Singh
- Department of Ageing Research, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India
| | - Divakar Singh
- School of Biochemical Engineering, IIT BHU, Varanasi, Uttar Pradesh, India
| | - Sutong Liu
- Juxing College of Digital Economics, Haikou University of Economics, Haikou, 570100, China
| | - Pradeep Srivastava
- School of Biochemical Engineering, IIT BHU, Varanasi, Uttar Pradesh, India.
| | - Chenzhong Li
- Biomedical Engineering, School of Medicine, The Chinese University of Hong Kong(Shenzhen), Shenzhen, 518172, China.
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Nagahawatte ND, Paskaranandavadivel N, Bear LR, Avci R, Cheng LK. A novel framework for the removal of pacing artifacts from bio-electrical recordings. Comput Biol Med 2023; 155:106673. [PMID: 36805227 DOI: 10.1016/j.compbiomed.2023.106673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/23/2023] [Accepted: 02/10/2023] [Indexed: 02/13/2023]
Abstract
BACKGROUND Electroceuticals provide clinical solutions for a range of disorders including Parkinson's disease, cardiac arrythmias and are emerging as a potential treatment option for gastrointestinal disorders. However, pre-clinical investigations are challenged by the large stimulation artifacts registered in bio-electrical recordings. METHOD A generalized framework capable of isolating and suppressing stimulation artifacts with minimal intervention was developed. Stimulation artifacts with different pulse-parameters in synthetic and experimental cardiac and gastrointestinal signals were detected using a Hampel filter and reconstructed using 3 methods: i) autoregression, ii) weighted mean, and iii) linear interpolation. RESULTS Synthetic stimulation artifacts with amplitudes of 2 mV and 4 mV and pulse-widths of 50 ms, 100 ms, and 200 ms were successfully isolated and the artifact window size remained uninfluenced by the pulse-amplitude, but was influenced by pulse-width (e.g., the autoregression method resulted in an identical Root Mean Square Error (RMSE) of 1.64 mV for artifacts with 200 ms pulse-width and both 2 mV and 4 mV amplitudes). The performance of autoregression (RMSE = 1.45 ± 0.16 mV) and linear interpolation (RMSE = 1.22 ± 0.14 mV) methods were comparable and better than weighted mean (RMSE = 5.54 ± 0.56 mV) for synthetic data. However, for experimental recordings, artifact removal by autoregression was superior to both linear interpolation and weighted mean approaches in gastric, small intestinal and cardiac recordings. CONCLUSIONS A novel signal processing framework enabled efficient analysis of bio-electrical recordings with stimulation artifacts. This will allow the bio-electrical events induced by stimulation protocols to be efficiently and systematically evaluated, resulting in improved stimulation therapies.
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Affiliation(s)
- Nipuni D Nagahawatte
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | | | - Laura R Bear
- IHU Liryc, Fondation Bordeaux Université, F-33600, Pessac-Bordeaux, France; INSERM, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, F-33000, Bordeaux, France; Université de Bordeaux, CRCTB, U1045, F-33000, Bordeaux, France
| | - Recep Avci
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Leo K Cheng
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand; Department of Surgery, Vanderbilt University, Nashville, TN, USA; Riddet Institute Centre of Research Excellence, Palmerston North, New Zealand.
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Niort BC, Recalde A, Cros C, Brette F. Critical Link between Calcium Regional Heterogeneity and Atrial Fibrillation Susceptibility in Sheep Left Atria. J Clin Med 2023; 12:jcm12030746. [PMID: 36769395 PMCID: PMC9917890 DOI: 10.3390/jcm12030746] [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: 11/28/2022] [Revised: 12/30/2022] [Accepted: 01/12/2023] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Atrial fibrillation is the most sustained form of arrhythmia in the human population that leads to important electrophysiological and structural cardiac remodeling as it progresses into a chronic form. Calcium is an established key player of cellular electrophysiology in the heart, yet to date, there is no information that maps calcium signaling across the left atrium. OBJECTIVE The aim of this study is to determine whether calcium signaling is homogenous throughout the different regions of the left atrium. This work tests the hypothesis that differences across the healthy left atrium contribute to a unique, region-dependent calcium cycling and participates in the pro-arrhythmic activity during atrial fibrillation. METHODS An animal model relevant to human cardiac function (the sheep) was used to characterize both the electrical activity and the calcium signaling of three distinct left atrium regions (appendage, free wall and pulmonary veins) in control conditions and after acetylcholine perfusion (5 μM) to induce acute atrial fibrillation. High-resolution dual calcium-voltage optical mapping on the left atria of sheep was performed to explore the spatiotemporal dynamics of calcium signaling in relation to electrophysiological properties. RESULTS Action potential duration (at 80% repolarization) was not significantly different in the three regions of interest for the three pacing sites. In contrast, the time to 50% calcium transient decay was significantly different depending on the region paced and recorded. Acetylcholine perfusion and burst pacing-induced atrial fibrillation when pulmonary veins and appendage regions were paced but not when the free wall region was. Dantrolene (a ryanodine receptor blocker) did not reduce atrial fibrillation susceptibility. CONCLUSION These data provide the first evidence of heterogenous calcium signaling across the healthy left atrium. Such basal regional differences may be exacerbated during the progression of atrial fibrillation and thus play a crucial role in focal arrhythmia initiation without ryanodine receptor gating modification.
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Affiliation(s)
- Barbara C. Niort
- Centre de Recherche Cardio-Thoracique de Bordeaux (CRCTB), Inserm U1045, Univeristé de Bordeaux, F-33000 Bordeaux, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, F-33600 Pessac, France
| | - Alice Recalde
- Centre de Recherche Cardio-Thoracique de Bordeaux (CRCTB), Inserm U1045, Univeristé de Bordeaux, F-33000 Bordeaux, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, F-33600 Pessac, France
| | - Caroline Cros
- Centre de Recherche Cardio-Thoracique de Bordeaux (CRCTB), Inserm U1045, Univeristé de Bordeaux, F-33000 Bordeaux, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, F-33600 Pessac, France
| | - Fabien Brette
- Centre de Recherche Cardio-Thoracique de Bordeaux (CRCTB), Inserm U1045, Univeristé de Bordeaux, F-33000 Bordeaux, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, F-33600 Pessac, France
- Phymedexp Inserm, CNRS, Université de Montpellier, CHRU, F-34295 Montpellier, France
- Correspondence:
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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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Haq KT, Cooper BL, Berk F, Posnack NG. The effect of sex and age on ex vivo cardiac electrophysiology: insight from a guinea pig model. Am J Physiol Heart Circ Physiol 2023; 324:H141-H154. [PMID: 36487188 PMCID: PMC9829463 DOI: 10.1152/ajpheart.00497.2022] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/14/2022]
Abstract
Highlighting the importance of sex as a biological variable, we recently reported sex differences in guinea pig in vivo electrocardiogram (ECG) measurements. However, substantial inconsistencies exist in this animal model, with conflicting reports of sex-specific differences in cardiac electrophysiology observed in vivo and in vitro. Herein, we evaluated whether sexual dimorphism persists in ex vivo preparations, using an isolated intact heart preparation. Pseudo-ECG recordings were collected in conjunction with dual optical mapping of transmembrane voltage and intracellular calcium from Langendorff-perfused hearts. In contrast to our in vivo results, we did not observe sex-specific differences in ECG parameters collected from isolated hearts. Furthermore, we observed significant age-specific differences in action potential duration (APD) and Ca2+ transient duration (CaD) during both normal sinus rhythm (NSR) and in response to dynamic pacing but only a modest sex-specific difference in CaD30. Similarly, the alternans fluctuation coefficient, conduction velocity during sinus rhythm or in response to pacing, and electrophysiology parameters (atrioventricular nodal effective refractory period, Wenckebach cycle length) were comparable between males and females. Results of our study suggest that the observed sex-specific differences in in vivo ECG parameters from guinea pigs are diminished in ex vivo isolated heart preparations, although age-specific patterns are prevalent. To assess sex as a biological variable in cardiac electrophysiology, a comprehensive approach may be necessary using both in vitro measurements from cardiomyocyte or intact heart preparations with secondary follow-up in vivo studies.NEW & NOTEWORTHY We evaluated whether the guinea pig heart has intrinsic sex-specific differences in cardiac electrophysiology. Although we observed sex-specific differences in in vivo ECGs, these differences did not persist ex vivo. Using a whole heart model, we observed similar APD, CaD, conduction velocity, and alternans susceptibility in males and females. We conclude that sex-specific differences in guinea pig cardiac electrophysiology are likely influenced by the in vivo environment and less dependent on the intrinsic electrical properties of the heart.
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Affiliation(s)
- Kazi T Haq
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, District of Columbia
- Children's National Heart Institute, Children's National Hospital, Washington, District of Columbia
| | - Blake L Cooper
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, District of Columbia
- Children's National Heart Institute, Children's National Hospital, Washington, District of Columbia
- Department of Pharmacology and Physiology, The George Washington University, Washington, District of Columbia
| | - Fiona Berk
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, District of Columbia
- Children's National Heart Institute, Children's National Hospital, Washington, District of Columbia
- Department of Pharmacology and Physiology, The George Washington University, Washington, District of Columbia
- Department of Biomedical Engineering, The George Washington University, Washington, District of Columbia
| | - Nikki Gillum Posnack
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, District of Columbia
- Children's National Heart Institute, Children's National Hospital, Washington, District of Columbia
- Department of Pharmacology and Physiology, The George Washington University, Washington, District of Columbia
- Department of Pediatrics, The George Washington University, Washington, District of Columbia
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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: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/11/2022] [Accepted: 10/17/2022] [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
- Department of Pharmacology, University of California Davis School of Medicine, Davis, California
| | - Alexey V Glukhov
- Department of Medicine, Cardiovascular Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Matthew W Kay
- Department of Biomedical Engineering, The George Washington University, Washington, District of Columbia
| | - Bastiaan J Boukens
- Department Physiology, University Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
- Department of Medical Biology, University of Amsterdam, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Nipavan Chiamvimonvat
- Department of Pharmacology, University of California Davis School of Medicine, Davis, California
- Department of Internal Medicine, University of California Davis School of Medicine, Davis, California
- Veterans Affairs Northern California Healthcare System, Mather, California
| | - Brian P Delisle
- Department of Physiology, University of Kentucky, Lexington, Kentucky
| | - Larissa Fabritz
- University Center of Cardiovascular Science, University Heart and Vascular Center, University Hospital Hamburg-Eppendorf with DZHK Hamburg/Kiel/Luebeck, Germany
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Thomas J Hund
- Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
- Department of Biomedical Engineering, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
| | - Bjorn C Knollmann
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Na Li
- Department of Medicine, Baylor College of Medicine, Houston, Texas
| | - Katherine T Murray
- Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Steven Poelzing
- Virginia Tech Carilon School of Medicine, Center for Heart and Reparative Medicine Research, Fralin Biomedical Research Institute at Virginia Tech, Roanoke, Virginia
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia
| | - T Alexander Quinn
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
- School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Carol Ann Remme
- Department of Experimental Cardiology, Heart Centre, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
| | - Stacey L Rentschler
- Cardiovascular Division, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri
| | - Robert A Rose
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Nikki G Posnack
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, District of Columbia
- Department of Pediatrics, George Washington University School of Medicine, Washington, District of Columbia
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19
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Koya T, Watanabe M, Natsui H, Kadosaka T, Koizumi T, Nakao M, Hagiwara H, Kamada R, Temma T, Anzai T. Pharmacological nNOS inhibition modified small-conductance Ca 2+-activated K + channel without altering Ca 2+ dynamics. Am J Physiol Heart Circ Physiol 2022; 323:H869-H878. [PMID: 36149772 DOI: 10.1152/ajpheart.00252.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Atrial fibrillation (AF) is associated with electrical remodeling processes that promote a substrate for the maintenance of AF. Although the small-conductance Ca2+-activated K+ (SK) channel is a key factor in atrial electrical remodeling, the mechanism of its activation remains unclear. Regional nitric oxide (NO) production by neuronal nitric oxide synthase (nNOS) is involved in atrial electrical remodeling. In this study, atrial tachyarrhythmia (ATA) induction and optical mapping were performed on perfused rat hearts. nNOS is pharmacologically inhibited by S-methylthiocitrulline (SMTC). The influence of the SK channel was examined using a specific channel inhibitor, apamin (APA). Parameters such as action potential duration (APD), conduction velocity, and calcium transient (CaT) were evaluated using voltage and calcium optical mapping. The dominant frequency was examined in the analysis of AF dynamics. SMTC (100 nM) increased the inducibility of ATA and apamin (100 nM) mitigated nNOS inhibition-induced arrhythmogenicity. SMTC caused abbreviations and enhanced the spatial dispersion of APD, which was reversed by apamin. By contrast, conduction velocity and other parameters associated with CaT were not affected by SMTC or apamin administration. Apamin reduced the frequency of SMTC-induced ATA. In summary, nNOS inhibition abbreviates APD by modifying the SK channels. A specific SK channel blocker, apamin, mitigated APD abbreviation without alteration of CaT, implying an underlying mechanism of posttranslational modification of SK channels.NEW & NOTEWORTHY We demonstrated that pharmacological nNOS inhibition increased the atrial arrhythmia inducibility and a specific small-conductance Ca2+-activated K+ channel blocker, apamin, reversed the enhanced atrial arrhythmia inducibility. Apamin mitigated APD abbreviation without alteration of Ca2+ transient, implying an underlying mechanism of posttranslational modification of SK channels.
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Affiliation(s)
- Taro Koya
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Masaya Watanabe
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Hiroyuki Natsui
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Takahide Kadosaka
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Takuya Koizumi
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Motoki Nakao
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Hikaru Hagiwara
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Rui Kamada
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Taro Temma
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Toshihisa Anzai
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
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20
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Dadson K, Thavendiranathan P, Hauck L, Grothe D, Azam MA, Stanley-Hasnain S, Mahiny-Shahmohammady D, Si D, Bokhari M, Lai PF, Massé S, Nanthakumar K, Billia F. Statins Protect Against Early Stages of Doxorubicin-induced Cardiotoxicity Through the Regulation of Akt Signaling and SERCA2. CJC Open 2022; 4:1043-1052. [PMID: 36562012 PMCID: PMC9764135 DOI: 10.1016/j.cjco.2022.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 08/10/2022] [Indexed: 12/25/2022] Open
Abstract
Background Doxorubicin-induced cardiomyopathy (DICM) is one of the complications that can limit treatment for a significant number of cancer patients. In animal models, the administration of statins can prevent the development of DICM. Therefore, the use of statins with anthracyclines potentially could enable cancer patients to complete their chemotherapy without added cardiotoxicity. The precise mechanism mediating the cardioprotection is not well understood. The purpose of this study is to determine the molecular mechanism by which rosuvastatin confers cardioprotection in a mouse model of DICM. Methods Rosuvastatin was intraperitoneally administered into adult male mice at 100 μg/kg daily for 7 days, followed by a single intraperitoneal doxorubicin injection at 10 mg/kg. Animals continued to receive rosuvastatin daily for an additional 14 days. Cardiac function was assessed by echocardiography. Optical calcium mapping was performed on retrograde Langendorff perfused isolated hearts. Ventricular tissue samples were analyzed by immunofluorescence microscopy, Western blotting, and quantitative polymerase chain reaction. Results Exposure to doxorubicin resulted in significantly reduced fractional shortening (27.4% ± 1.11% vs 40% ± 5.8% in controls; P < 0.001) and re-expression of the fetal gene program. However, we found no evidence of maladaptive cardiac hypertrophy or adverse ventricular remodeling in mice exposed to this dose of doxorubicin. In contrast, rosuvastatin-doxorubicin-treated mice maintained their cardiac function (39% ± 1.26%; P < 0.001). Mechanistically, the effect of rosuvastatin was associated with activation of Akt and phosphorylation of phospholamban with preserved sarcoplasmic/endoplasmic reticulum Ca2+ transporting 2 (SERCA2)-mediated Ca2+ reuptake. These effects occurred independently of perturbations in ryanodine receptor 2 function. Conclusions Rosuvastatin counteracts the cardiotoxic effects of doxorubicin by directly targeting sarcoplasmic calcium cycling.
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Affiliation(s)
- Keith Dadson
- Toronto General Hospital Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Paaladinesh Thavendiranathan
- Ted Rogers Program in Cardiotoxicity Prevention, Peter Munk Cardiac Centre, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Ludger Hauck
- Toronto General Hospital Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Daniela Grothe
- Toronto General Hospital Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Mohammed Ali Azam
- Toronto General Hospital Research Institute, University of Toronto, Toronto, Ontario, Canada,The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada
| | - Shanna Stanley-Hasnain
- Toronto General Hospital Research Institute, University of Toronto, Toronto, Ontario, Canada
| | | | - Daoyuan Si
- Toronto General Hospital Research Institute, University of Toronto, Toronto, Ontario, Canada,The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada
| | - Mahmoud Bokhari
- Toronto General Hospital Research Institute, University of Toronto, Toronto, Ontario, Canada,The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada
| | - Patrick F.H. Lai
- Toronto General Hospital Research Institute, University of Toronto, Toronto, Ontario, Canada,The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada
| | - Stéphane Massé
- Toronto General Hospital Research Institute, University of Toronto, Toronto, Ontario, Canada,The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada
| | - Kumaraswamy Nanthakumar
- Toronto General Hospital Research Institute, University of Toronto, Toronto, Ontario, Canada,The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada
| | - Filio Billia
- Toronto General Hospital Research Institute, University of Toronto, Toronto, Ontario, Canada,Corresponding author: Dr Filio Billia, Toronto General Hospital Research Institute, University Health Network, University of Toronto, 101 College St., Toronto, Ontario, M5G 1L7 Canada. Tel.: +1-416-340-4800 x6805; fax: +1-416-340-4012.
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21
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Pasqualin C, Gannier F, Yu A, Benoist D, Findlay I, Bordy R, Bredeloux P, Maupoil V. Spiky: An ImageJ Plugin for Data Analysis of Functional Cardiac and Cardiomyocyte Studies. J Imaging 2022; 8:jimaging8040095. [PMID: 35448222 PMCID: PMC9026474 DOI: 10.3390/jimaging8040095] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/25/2022] [Accepted: 03/29/2022] [Indexed: 02/04/2023] Open
Abstract
Introduction and objective: Nowadays, investigations of heart physiology and pathophysiology rely more and more upon image analysis, whether for the detection and characterization of events in single cells or for the mapping of events and their characteristics across an entire tissue. These investigations require extensive skills in image analysis and/or expensive software, and their reproducibility may be a concern. Our objective was to build a robust, reliable and open-source software tool to quantify excitation–contraction related experimental data at multiple scales, from single isolated cells to the whole heart. Methods and results: A free and open-source ImageJ plugin, Spiky, was developed to detect and analyze peaks in experimental data streams. It allows rapid and easy analysis of action potentials, intracellular calcium transient and contraction data from cardiac research experiments. As shown in the provided examples, both classical bi-dimensional data (XT signals) and video data obtained from confocal microscopy and optical mapping experiments (XYT signals) can be analyzed. Spiky was written in ImageJ Macro Language and JAVA, and works under Windows, Mac and Linux operating systems. Conclusion: Spiky provides a complete working interface to process and analyze cardiac physiology research data.
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Affiliation(s)
- Côme Pasqualin
- Groupe Physiologie des Cellules Cardiaques et Vasculaires, Université de Tours, EA4245 Transplantation, Immunologie, Inflammation, 37000 Tours, France; (F.G.); (A.Y.); (I.F.); (R.B.); (P.B.); (V.M.)
- Correspondence: ; Tel.: +33-247-367-335
| | - François Gannier
- Groupe Physiologie des Cellules Cardiaques et Vasculaires, Université de Tours, EA4245 Transplantation, Immunologie, Inflammation, 37000 Tours, France; (F.G.); (A.Y.); (I.F.); (R.B.); (P.B.); (V.M.)
| | - Angèle Yu
- Groupe Physiologie des Cellules Cardiaques et Vasculaires, Université de Tours, EA4245 Transplantation, Immunologie, Inflammation, 37000 Tours, France; (F.G.); (A.Y.); (I.F.); (R.B.); (P.B.); (V.M.)
| | - David Benoist
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, 33600 Pessac, France;
- Universite de Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique, U1045, 33000 Bordeaux, France
| | - Ian Findlay
- Groupe Physiologie des Cellules Cardiaques et Vasculaires, Université de Tours, EA4245 Transplantation, Immunologie, Inflammation, 37000 Tours, France; (F.G.); (A.Y.); (I.F.); (R.B.); (P.B.); (V.M.)
| | - Romain Bordy
- Groupe Physiologie des Cellules Cardiaques et Vasculaires, Université de Tours, EA4245 Transplantation, Immunologie, Inflammation, 37000 Tours, France; (F.G.); (A.Y.); (I.F.); (R.B.); (P.B.); (V.M.)
| | - Pierre Bredeloux
- Groupe Physiologie des Cellules Cardiaques et Vasculaires, Université de Tours, EA4245 Transplantation, Immunologie, Inflammation, 37000 Tours, France; (F.G.); (A.Y.); (I.F.); (R.B.); (P.B.); (V.M.)
| | - Véronique Maupoil
- Groupe Physiologie des Cellules Cardiaques et Vasculaires, Université de Tours, EA4245 Transplantation, Immunologie, Inflammation, 37000 Tours, France; (F.G.); (A.Y.); (I.F.); (R.B.); (P.B.); (V.M.)
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22
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Reiche MA, Aaron JS, Boehm U, DeSantis MC, Hobson CM, Khuon S, Lee RM, Chew TL. When light meets biology - how the specimen affects quantitative microscopy. J Cell Sci 2022; 135:274812. [PMID: 35319069 DOI: 10.1242/jcs.259656] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Fluorescence microscopy images should not be treated as perfect representations of biology. Many factors within the biospecimen itself can drastically affect quantitative microscopy data. Whereas some sample-specific considerations, such as photobleaching and autofluorescence, are more commonly discussed, a holistic discussion of sample-related issues (which includes less-routine topics such as quenching, scattering and biological anisotropy) is required to appropriately guide life scientists through the subtleties inherent to bioimaging. Here, we consider how the interplay between light and a sample can cause common experimental pitfalls and unanticipated errors when drawing biological conclusions. Although some of these discrepancies can be minimized or controlled for, others require more pragmatic considerations when interpreting image data. Ultimately, the power lies in the hands of the experimenter. The goal of this Review is therefore to survey how biological samples can skew quantification and interpretation of microscopy data. Furthermore, we offer a perspective on how to manage many of these potential pitfalls.
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Affiliation(s)
- Michael A Reiche
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147, USA
| | - Jesse S Aaron
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147, USA
| | - Ulrike Boehm
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147, USA
| | - Michael C DeSantis
- Light Microscopy Facility, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147,USA
| | - Chad M Hobson
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147, USA
| | - Satya Khuon
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147, USA.,Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147, USA
| | - Rachel M Lee
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147, USA
| | - Teng-Leong Chew
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147, USA.,Light Microscopy Facility, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147,USA
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23
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Xia L, Wang X, Yao W, Wang M, Zhu J. Lipopolysaccharide increases exosomes secretion from endothelial progenitor cells by toll-like receptor 4 dependent mechanism. Biol Cell 2022; 114:127-137. [PMID: 35235701 DOI: 10.1111/boc.202100086] [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: 11/02/2021] [Revised: 01/18/2022] [Accepted: 02/17/2022] [Indexed: 11/27/2022]
Abstract
Endothelial progenitor cells (EPCs) can exert angiogenic effects by a paracrine mechanism, where exosomes work as an important mediator. Recent studies reported functional expression of toll-like receptor (TLR) 4 on human EPCs and dose-dependent effects of lipopolysaccharide (LPS) on EPC angiogenic properties. To study on the effects of TLR4/LPS signaling on EPC-derived exosomes (Exo) and involved mechanisms, we investigated the effect of LPS on exosomes secretion from human EPC and tested Exo functions by senescence-associated β-galactosidase activity assay and reactive oxygen species (ROS) related H2 DCF-DA assay. To clarify the mechanism, we examined the changes in intracellular calcium levels and multivesicular bodies (MVBs) development in EPC. We employed the inhibitors of the plasma membrane Ca 2+ -ATPase (PMCA), endoplasmic reticulum Ca 2+ -ATPase (ERCA), PLC-IP3 pathway and store-operated calcium entry to assess the effects of LPS on calcium signalings which critical for exosome secretion. LPS induced the release of Exo in a TLR4-dependent manner in vitro, which effect can be partly abrogated by the membrane-permeable IP 3 R antagonist, 2-aminoethyl diphenylborinate (2-APB), but not PLC inhibitor, U-73122. The LPS can significantly delay the fallback of [Ca 2+ ]i after isolating the cellular PMCA activity, and disturb PMCA 1/4 expression. The distribution of elevated intracellular calcium seemed coincident with the development of MVBs. Furthermore, the LPS-induced Exo maintained valid anti-oxidation/senescence properties. The PMCA and ER Ca 2+ release mechanism may contribute to the pro-exosomal effects of LPS on EPC, which is valuable for potential pro-regenerative application in future. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Liang Xia
- Department of Clinical Medicine, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Xiaotian Wang
- Department of Clinical Medicine, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Weidong Yao
- Department of Clinical Medicine, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Meihui Wang
- Biomedical Research (Therapy) Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Junhui Zhu
- Department of Cardiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
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24
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Cumberland MJ, Riebel LL, Roy A, O’Shea C, Holmes AP, Denning C, Kirchhof P, Rodriguez B, Gehmlich K. Basic Research Approaches to Evaluate Cardiac Arrhythmia in Heart Failure and Beyond. Front Physiol 2022; 13:806366. [PMID: 35197863 PMCID: PMC8859441 DOI: 10.3389/fphys.2022.806366] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 01/10/2022] [Indexed: 12/20/2022] Open
Abstract
Patients with heart failure often develop cardiac arrhythmias. The mechanisms and interrelations linking heart failure and arrhythmias are not fully understood. Historically, research into arrhythmias has been performed on affected individuals or in vivo (animal) models. The latter however is constrained by interspecies variation, demands to reduce animal experiments and cost. Recent developments in in vitro induced pluripotent stem cell technology and in silico modelling have expanded the number of models available for the evaluation of heart failure and arrhythmia. An agnostic approach, combining the modalities discussed here, has the potential to improve our understanding for appraising the pathology and interactions between heart failure and arrhythmia and can provide robust and validated outcomes in a variety of research settings. This review discusses the state of the art models, methodologies and techniques used in the evaluation of heart failure and arrhythmia and will highlight the benefits of using them in combination. Special consideration is paid to assessing the pivotal role calcium handling has in the development of heart failure and arrhythmia.
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Affiliation(s)
- Max J. Cumberland
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Leto L. Riebel
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Ashwin Roy
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Christopher O’Shea
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Andrew P. Holmes
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Chris Denning
- Stem Cell Biology Unit, Biodiscovery Institute, British Heart Foundation Centre for Regenerative Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Paulus Kirchhof
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- University Heart and Vascular Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Blanca Rodriguez
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Katja Gehmlich
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford and British Heart Foundation Centre of Research Excellence Oxford, Oxford, United Kingdom
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25
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Liao J, Zhang S, Yang S, Lu Y, Lu K, Wu Y, Wu Q, Zhao N, Dong Q, Chen L, Du Y. Interleukin-6-Mediated-Ca 2+ Handling Abnormalities Contributes to Atrial Fibrillation in Sterile Pericarditis Rats. Front Immunol 2022; 12:758157. [PMID: 34975847 PMCID: PMC8716408 DOI: 10.3389/fimmu.2021.758157] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 11/30/2021] [Indexed: 02/05/2023] Open
Abstract
Pre-existing Ca2+ handling abnormalities constitute the arrhythmogenic substrate in patients developing postoperative atrial fibrillation (POAF), a common complication after cardiac surgery. Postoperative interleukin (IL)-6 levels are associated with atrial fibrosis in several animal models of POAF, contributing to atrial arrhythmias. Here, we hypothesize that IL-6-mediated-Ca2+ handling abnormalities contribute to atrial fibrillation (AF) in sterile pericarditis (SP) rats, an animal model of POAF. SP was induced in rats by dusting atria with sterile talcum powder. Anti-rat-IL-6 antibody (16.7 μg/kg) was administered intraperitoneally at 30 min after the recovery of anesthesia. In vivo electrophysiology, ex vivo optical mapping, western blots, and immunohistochemistry were performed to elucidate mechanisms of AF susceptibility. IL-6 neutralization ameliorated atrial inflammation and fibrosis, as well as AF susceptibility in vivo and the frequency of atrial ectopy and AF with a reentrant pattern in SP rats ex vivo. IL-6 neutralization reversed the prolongation and regional heterogeneity of Ca2+ transient duration, relieved alternans, reduced the incidence of discordant alternans, and prevented the reduction and regional heterogeneity of the recovery ratio of Ca2+ transient. In agreement, western blots showed that IL-6 neutralization reversed the reduction in the expression of ryanodine receptor 2 (RyR2) and phosphorylated phospholamban. Acute IL-6 administration to isolated rat hearts recapitulated partial Ca2+ handling phenotype in SP rats. In addition, intraperitoneal IL-6 administration to rats increased AF susceptibility, independent of fibrosis. Our results reveal that IL-6-mediated-Ca2+ handling abnormalities in SP rats, especially RyR2-dysfunction, independent of IL-6-induced-fibrosis, early contribute to the development of POAF by increasing propensity for arrhythmogenic alternans.
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Affiliation(s)
- Jie Liao
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Research Center of Ion Channelopathy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department of Cardiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Shaoshao Zhang
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Research Center of Ion Channelopathy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shuaitao Yang
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Research Center of Ion Channelopathy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yang Lu
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Research Center of Ion Channelopathy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kai Lu
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Research Center of Ion Channelopathy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yuwei Wu
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Research Center of Ion Channelopathy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qiongfeng Wu
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Research Center of Ion Channelopathy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ning Zhao
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Research Center of Ion Channelopathy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qian Dong
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Research Center of Ion Channelopathy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lei Chen
- Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Yimei Du
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Research Center of Ion Channelopathy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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26
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Baillie JS, Stoyek MR, Quinn TA. Seeing the Light: The Use of Zebrafish for Optogenetic Studies of the Heart. Front Physiol 2021; 12:748570. [PMID: 35002753 PMCID: PMC8733579 DOI: 10.3389/fphys.2021.748570] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/19/2021] [Indexed: 11/13/2022] Open
Abstract
Optogenetics, involving the optical measurement and manipulation of cellular activity with genetically encoded light-sensitive proteins ("reporters" and "actuators"), is a powerful experimental technique for probing (patho-)physiological function. Originally developed as a tool for neuroscience, it has now been utilized in cardiac research for over a decade, providing novel insight into the electrophysiology of the healthy and diseased heart. Among the pioneering cardiac applications of optogenetic actuators were studies in zebrafish, which first demonstrated their use for precise spatiotemporal control of cardiac activity. Zebrafish were also adopted early as an experimental model for the use of optogenetic reporters, including genetically encoded voltage- and calcium-sensitive indicators. Beyond optogenetic studies, zebrafish are becoming an increasingly important tool for cardiac research, as they combine many of the advantages of integrative and reduced experimental models. The zebrafish has striking genetic and functional cardiac similarities to that of mammals, its genome is fully sequenced and can be modified using standard techniques, it has been used to recapitulate a variety of cardiac diseases, and it allows for high-throughput investigations. For optogenetic studies, zebrafish provide additional advantages, as the whole zebrafish heart can be visualized and interrogated in vivo in the transparent, externally developing embryo, and the relatively small adult heart allows for in situ cell-specific observation and control not possible in mammals. With the advent of increasingly sophisticated fluorescence imaging approaches and methods for spatially-resolved light stimulation in the heart, the zebrafish represents an experimental model with unrealized potential for cardiac optogenetic studies. In this review we summarize the use of zebrafish for optogenetic investigations in the heart, highlighting their specific advantages and limitations, and their potential for future cardiac research.
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Affiliation(s)
- Jonathan S. Baillie
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
| | - Matthew R. Stoyek
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
| | - T. Alexander Quinn
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
- School of Biomedical Engineering, Dalhousie University, Halifax, NS, Canada
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27
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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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28
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Azam MA, Chakraborty P, Bokhari MM, Dadson K, Du B, Massé S, Si D, Niri A, Aggarwal AK, Lai PF, Riazi S, Billia F, Nanthakumar K. Cardioprotective effects of dantrolene in doxorubicin-induced cardiomyopathy in mice. Heart Rhythm O2 2021; 2:733-741. [PMID: 34988524 PMCID: PMC8710625 DOI: 10.1016/j.hroo.2021.08.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Doxorubicin (Dox) is a potent chemotherapeutic agent, but its usage is limited by dose-dependent cardiotoxicity. Intracellular calcium dysregulation has been reported to be involved in doxorubicin-induced cardiomyopathy (DICM). The cardioprotective role of RyR stabilizer dantrolene (Dan) on the calcium dynamics of DICM has not yet been explored. OBJECTIVE To evaluate the effects of dantrolene on intracellular calcium dysregulation and cardiac contractile function in a DICM model. METHODS Adult male C57BL/6 mice were randomized into 4 groups: (1) Control, (2) Dox Only, (3) Dan Only, and (4) Dan + Dox. Fractional shortening (FS) and left ventricular ejection fraction (LVEF) were assessed by echocardiography. In addition, mice were sacrificed 2 weeks after doxorubicin injection for optical mapping of the heart in a Langendorff setup. RESULTS Treatment with Dox was associated with a reduction in both FS and LVEF at 2 weeks (P < .0001) and 4 weeks (P < .006). Dox treatment was also associated with prolongation of calcium transient durations CaTD50 (P = .0005) and CaTD80 (P < .0001) and reduction of calcium amplitude alternans ratio (P < .0001). Concomitant treatment with Dan prevented the Dox-induced decline in FS and LVEF (P < .002 at both 2 and 4 weeks). Dan also prevented Dox-induced prolongation of CaTD50 and CaTD80 and improved the CaT alternans ratio (P < .0001). Finally, calcium transient rise time was increased in the doxorubicin-treated group, indicating RyR2 dyssynchrony, and dantrolene prevented this prolongation (P = .02). CONCLUSION Dantrolene prevents cardiac contractile dysfunction following doxorubicin treatment by mitigating dysregulation of calcium dynamics.
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Affiliation(s)
- Mohammed Ali Azam
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Praloy Chakraborty
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Canada
- Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Mahmoud M. Bokhari
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Canada
- Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Keith Dadson
- Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Beibei Du
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Stéphane Massé
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Daoyuan Si
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Ahmed Niri
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Arjun K. Aggarwal
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Patrick F.H. Lai
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Sheila Riazi
- Malignant Hyperthermia Investigation Unit, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Filio Billia
- Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Kumaraswamy Nanthakumar
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Canada
- Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, Canada
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29
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Müllenbroich MC, Kelly A, Acker C, Bub G, Bruegmann T, Di Bona A, Entcheva E, Ferrantini C, Kohl P, Lehnart SE, Mongillo M, Parmeggiani C, Richter C, Sasse P, Zaglia T, Sacconi L, Smith GL. Novel Optics-Based Approaches for Cardiac Electrophysiology: A Review. Front Physiol 2021; 12:769586. [PMID: 34867476 PMCID: PMC8637189 DOI: 10.3389/fphys.2021.769586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 10/18/2021] [Indexed: 12/31/2022] Open
Abstract
Optical techniques for recording and manipulating cellular electrophysiology have advanced rapidly in just a few decades. These developments allow for the analysis of cardiac cellular dynamics at multiple scales while largely overcoming the drawbacks associated with the use of electrodes. The recent advent of optogenetics opens up new possibilities for regional and tissue-level electrophysiological control and hold promise for future novel clinical applications. This article, which emerged from the international NOTICE workshop in 2018, reviews the state-of-the-art optical techniques used for cardiac electrophysiological research and the underlying biophysics. The design and performance of optical reporters and optogenetic actuators are reviewed along with limitations of current probes. The physics of light interaction with cardiac tissue is detailed and associated challenges with the use of optical sensors and actuators are presented. Case studies include the use of fluorescence recovery after photobleaching and super-resolution microscopy to explore the micro-structure of cardiac cells and a review of two photon and light sheet technologies applied to cardiac tissue. The emergence of cardiac optogenetics is reviewed and the current work exploring the potential clinical use of optogenetics is also described. Approaches which combine optogenetic manipulation and optical voltage measurement are discussed, in terms of platforms that allow real-time manipulation of whole heart electrophysiology in open and closed-loop systems to study optimal ways to terminate spiral arrhythmias. The design and operation of optics-based approaches that allow high-throughput cardiac electrophysiological assays is presented. Finally, emerging techniques of photo-acoustic imaging and stress sensors are described along with strategies for future development and establishment of these techniques in mainstream electrophysiological research.
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Affiliation(s)
| | - Allen Kelly
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Corey Acker
- Center for Cell Analysis and Modeling, UConn Health, Farmington, CT, United States
| | - Gil Bub
- Department of Physiology, McGill University, Montréal, QC, Canada
| | - Tobias Bruegmann
- Institute for Cardiovascular Physiology, University Medical Center Goettingen, Goettingen, Germany
| | - Anna Di Bona
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Padova, Italy
| | - Emilia Entcheva
- Department of Biomedical Engineering, The George Washington University, Washington, DC, United States
| | | | - Peter Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Center and Medical Faculty, University of Freiburg, Freiburg, Germany
| | - Stephan E. Lehnart
- Heart Research Center Göttingen, University Medical Center Göttingen, Göttingen, Germany
- Department of Cardiology and Pneumology, Georg-August University Göttingen, Göttingen, Germany
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), University of Göttingen, Göttingen, Germany
| | - Marco Mongillo
- Department of Biomedical Sciences, University of Padova, Padova, Italy
- Veneto Institute of Molecular Medicine, Padova, Italy
| | | | - Claudia Richter
- German Primate Center - Leibniz Institute for Primate Research, Göttingen, Germany
| | - Philipp Sasse
- Institute of Physiology I, Medical Faculty, University of Bonn, Bonn, Germany
| | - Tania Zaglia
- Department of Biomedical Sciences, University of Padova, Padova, Italy
- Veneto Institute of Molecular Medicine, Padova, Italy
| | - Leonardo Sacconi
- European Laboratory for Nonlinear Spectroscopy, Sesto Fiorentino, Italy
- Institute for Experimental Cardiovascular Medicine, University Heart Center and Medical Faculty, University of Freiburg, Freiburg, Germany
- National Institute of Optics, National Research Council, Florence, Italy
| | - Godfrey L. Smith
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom
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30
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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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31
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Takase B, Higashimura Y, Asahina H, Ishihara M, Sakai H. Liposome-encapsulated hemoglobin (HbV) transfusion rescues rats undergoing progressive lethal 85% hemorrhage as a result of an anti-arrhythmogenic effect on the myocardium. Artif Organs 2021; 45:1391-1404. [PMID: 34219238 DOI: 10.1111/aor.14033] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/04/2021] [Accepted: 06/28/2021] [Indexed: 12/28/2022]
Abstract
Liposome-encapsulated hemoglobin vesicles (HbV) can serve as a blood substitute with oxygen-carrying capacity comparable to that of human blood and lethal hemorrhage is associated with lethal arrhythmias. To investigate the resuscitation effect of HbV on lethal hemorrhage and anti-arrhythmogenesis, we performed optical mapping analysis (OMP) and electrophysiological study (EPS) in graded blood exchange (85% blood loss) in the rat model. We also measured cardiac autonomic activity, as assessed by heart rate variability (HRV), and changes in plasma norepinephrine and left ventricle ejection fraction (LVEF) by echocardiography. Pathological study on Connexin43 was performed. A 5% albumin (ALB group), washed rat erythrocytes (wRBC group), and HbV (HbV group) were used as a resuscitation fluid. The survival effects over 24 hours were examined. All rats died in the ALB group, whereas almost all survived for 24-hours period in wRBC and HbV groups. OMP showed impaired action potential duration dispersion (APDd) in the ALB group, whereas normal APDs in HbV and wRBC groups. Lethal arrhythmias were induced by EPS in the ALB group, but not in wRBC and HbV groups. HRV indices, LVEF, Connexin43 were preserved in HbV and wRBC groups. Lethal hemorrhage causes lethal arrhythmias in the presence of impaired APDd. HbV acutely rescues lethal hemorrhage by preventing lethal arrhythmias and preserving arrhythmogenic factors.
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Affiliation(s)
- Bonpei Takase
- Department of Intensive Care Medicine, National Defense Medical College, Tokorozawa, Japan
| | - Yuko Higashimura
- Department of Intensive Care Medicine, National Defense Medical College, Tokorozawa, Japan
| | - Haruka Asahina
- Department of Critical Care Medicine, National Defense Medical College, Tokorozawa, Japan
| | - Masayuki Ishihara
- Division of Biomedical Engineering, National Defense Medical College Research Institute, Tokorozawa, Japan
| | - Hiromi Sakai
- Department of Chemistry, School of Medicine, Nara Medical University, Kashihara, Japan
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32
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Charrez B, Charwat V, Siemons BA, Goswami I, Sakolish C, Luo YS, Finsberg H, Edwards AG, Miller EW, Rusyn I, Healy KE. Heart Muscle Microphysiological System for Cardiac Liability Prediction of Repurposed COVID-19 Therapeutics. Front Pharmacol 2021; 12:684252. [PMID: 34421592 PMCID: PMC8378272 DOI: 10.3389/fphar.2021.684252] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 07/05/2021] [Indexed: 12/27/2022] Open
Abstract
Despite global efforts, it took 7 months between the proclamation of global SARS-CoV-2 pandemic and the first FDA-approved treatment for COVID-19. During this timeframe, clinicians focused their efforts on repurposing drugs, such as hydroxychloroquine (HCQ) or azithromycin (AZM) to treat hospitalized COVID-19 patients. While clinical trials are time-consuming, the exponential increase in hospitalizations compelled the FDA to grant an emergency use authorization for HCQ and AZM as treatment for COVID-19, although there was limited evidence of their combined efficacy and safety. The authorization was revoked 4 months later, giving rise to controversial political and scientific debates illustrating important challenges such as premature authorization of potentially ineffective or unsafe therapeutics, while diverting resources from screening of effective drugs. Here we report on a preclinical drug screening platform, a cardiac microphysiological system (MPS), to rapidly identify clinically relevant cardiac liabilities associated with HCQ and AZM. The cardiac MPS is a microfabricated fluidic system in which cardiomyocytes derived from human induced pluripotent stem cells self-arrange into a uniaxially beating tissue. The drug response was measured using outputs that correlate with clinical measurements such as action potential duration (proxy for clinical QT interval) and drug-biomarker pairing. The cardiac MPS predicted clinical arrhythmias associated with QT prolongation and rhythm instabilities in tissues treated with HCQ. We found no change in QT interval upon acute exposure to AZM, while still observing a significant increase in arrhythmic events. These results suggest that this MPS can not only predict arrhythmias, but it can also identify arrhythmias even when QT prolongation is absent. When exposed to HCQ and AZM polytherapy, this MPS faithfully reflected clinical findings, in that the combination of drugs synergistically increased QT interval when compared to single drug exposure, while not worsening the overall frequency of arrhythmic events. The high content cardiac MPS can rapidly evaluate the cardiac safety of potential therapeutics, ultimately accelerating patients' access to safe and effective treatments.
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Affiliation(s)
- Bérénice Charrez
- Department of Bioengineering and California Institute for Quantitative Biosciences (QB3), University of California at Berkeley, Berkeley, CA, United States
| | - Verena Charwat
- Department of Bioengineering and California Institute for Quantitative Biosciences (QB3), University of California at Berkeley, Berkeley, CA, United States
| | - Brian A. Siemons
- Department of Bioengineering and California Institute for Quantitative Biosciences (QB3), University of California at Berkeley, Berkeley, CA, United States
| | - Ishan Goswami
- Department of Bioengineering and California Institute for Quantitative Biosciences (QB3), University of California at Berkeley, Berkeley, CA, United States
| | - Courtney Sakolish
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States
| | - Yu-Syuan Luo
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States
| | | | - Andrew G. Edwards
- Department of Pharmacology, School of Medicine, University of California at Davis, Davis, CA, United States
| | - Evan W. Miller
- Department of Chemistry, University of California at Berkeley, Berkeley, CA, United States
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, United States
- Helen Wills Neuroscience Institute, University of California at Berkeley, Berkeley, CA, United States
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States
| | - Kevin E. Healy
- Department of Bioengineering and California Institute for Quantitative Biosciences (QB3), University of California at Berkeley, Berkeley, CA, United States
- Department of Materials Science and Engineering, University of California at Berkeley, Berkeley, CA, United States
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33
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Dries E, Bardi I, Nunez-Toldra R, Meijlink B, Terracciano CM. CaMKII inhibition reduces arrhythmogenic Ca2+ events in subendocardial cryoinjured rat living myocardial slices. J Gen Physiol 2021; 153:212078. [PMID: 33956073 PMCID: PMC8105719 DOI: 10.1085/jgp.202012737] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 04/13/2021] [Indexed: 01/08/2023] Open
Abstract
Spontaneous Ca2+ release (SCR) can cause triggered activity and initiate arrhythmias. Intrinsic transmural heterogeneities in Ca2+ handling and their propensity to disease remodeling may differentially modulate SCR throughout the left ventricular (LV) wall and cause transmural differences in arrhythmia susceptibility. Here, we aimed to dissect the effect of cardiac injury on SCR in different regions in the intact LV myocardium using cryoinjury on rat living myocardial slices (LMS). We studied SCR under proarrhythmic conditions using a fluorescent Ca2+ indicator and high-resolution imaging in LMS from the subendocardium (ENDO) and subepicardium (EPI). Cryoinjury caused structural remodeling, with loss in T-tubule density and an increased time of Ca2+ transients to peak after injury. In ENDO LMS, the Ca2+ transient amplitude and decay phase were reduced, while these were not affected in EPI LMS after cryoinjury. The frequency of spontaneous whole-slice contractions increased in ENDO LMS without affecting EPI LMS after injury. Cryoinjury caused an increase in foci that generates SCR in both ENDO and EPI LMS. In ENDO LMS, SCRs were more closely distributed and had reduced latencies after cryoinjury, whereas this was not affected in EPI LMS. Inhibition of CaMKII reduced the number, distribution, and latencies of SCR, as well as whole-slice contractions in ENDO LMS, but not in EPI LMS after cryoinjury. Furthermore, CaMKII inhibition did not affect the excitation–contraction coupling in cryoinjured ENDO or EPI LMS. In conclusion, we demonstrate increased arrhythmogenic susceptibility in the injured ENDO. Our findings show involvement of CaMKII and highlight the need for region-specific targeting in cardiac therapies.
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Affiliation(s)
- Eef Dries
- National Heart and Lung Institute, Imperial College London, London, UK.,Lab of Experimental Cardiology, Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium
| | - Ifigeneia Bardi
- National Heart and Lung Institute, Imperial College London, London, UK
| | | | - Bram Meijlink
- National Heart and Lung Institute, Imperial College London, London, UK
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Azam MA, Chakraborty P, Si D, Du B, Massé S, Lai PFH, Ha ACT, Nanthakumar K. Anti-arrhythmic and inotropic effects of empagliflozin following myocardial ischemia. Life Sci 2021; 276:119440. [PMID: 33781832 DOI: 10.1016/j.lfs.2021.119440] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 03/10/2021] [Accepted: 03/17/2021] [Indexed: 12/26/2022]
Abstract
BACKGROUND Empagliflozin (EMPA) reduces heart failure hospitalization and mortality. The benefit in terms of ventricular arrhythmia and contractility has not been explored. OBJECTIVE To determine the direct effects of EMPA on ventricular arrhythmia and cardiac contractility in an ex-vivo model of global ischemia-reperfusion (I/R). METHODS Langendorff-perfused rabbit hearts were subjected to 30 min of complete perfusion arrest and reperfusion. Either EMPA (1 μM) or normal saline (controls) was then infused into the perfusate in a randomized fashion. Ten minutes following drug infusion, calcium imaging was performed. At the end of each experiment, the heart was electrically stimulated 5 times to assess the inducibility of ventricular fibrillation (VF). In a separate series of experiments, left ventricular (LV) pressure and epicardial NADH fluorescence were simultaneously recorded. LV specimens were then collected for western blotting. RESULTS Post-ischemia, EMPA treatment was associated with reduction in the induction of VF >10s (rate of induction: 16.7 ± 3.3% vs. 60 ± 8.7% in control hearts, p = 0.003), improvement of LV developed pressure (LVDP; 68.10 ± 9.02% vs. 47.61 ± 5.15% in controls, p = 0.03) and reduction of NADH fluorescence (87.42 ± 2.79% vs. 112.88 ± 2.27% in control hearts, p = 0.04) along with an increase in NAD+/NADH ratio (2.75 ± 0.55 vs. 1.09 ± 0.32 in the control group, p = 0.04) A higher calcium amplitude alternans threshold was also observed with EMPA-treatment (5.42 ± 0.1 Hz vs. 4.75 ± 0.1 Hz in controls, p = 0.006). Sodium-glucose co-transporter-2 (SGLT2) expression was not detected in LV tissues. CONCLUSIONS EMPA treatment reduced ventricular arrhythmia vulnerability and mitigated contractile dysfunction in the global I/R model while improving calcium cycling and mitochondrial redox by SGLT2-independent mechanisms.
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Affiliation(s)
- Mohammed Ali Azam
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Canada
| | - Praloy Chakraborty
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Canada
| | - Daoyuan Si
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Canada
| | - BeiBei Du
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Canada
| | - Stéphane Massé
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Canada
| | - Patrick F H Lai
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Canada
| | - Andrew C T Ha
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Canada; Toronto General Hospital, Canada
| | - Kumaraswamy Nanthakumar
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Canada.
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Du B, Chakraborty P, Azam MA, Massé S, Lai PFH, Niri A, Si D, Thavendiranathan P, Abdel-Qadir H, Billia F, Nanthakumar K. Acute Effects of Ibrutinib on Ventricular Arrhythmia in Spontaneously Hypertensive Rats. JACC: CARDIOONCOLOGY 2020; 2:614-629. [PMID: 34396273 PMCID: PMC8352013 DOI: 10.1016/j.jaccao.2020.08.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 08/26/2020] [Accepted: 08/30/2020] [Indexed: 12/19/2022]
Abstract
Background The Bruton's Tyrosine Kinase Inhibitor ibrutinib is associated with ventricular arrhythmia (VA) and sudden death. However, the pro-arrhythmic electrophysiological dysregulation that results from ibrutinib with age and cardiovascular disease is unknown. Objectives This study sought to investigate the acute effects of ibrutinib on left ventricular (LV) VA vulnerability, cytosolic calcium dynamics, and membrane electrophysiology in old and young spontaneous hypertensive rats (SHRs). Methods Langendorff-perfused hearts of young (10 to 14 weeks) and old (10 to 14 months) SHRs were treated with ibrutinib (0.1 μmol/l) or vehicle for 30 min. Simultaneously, LV epicardial action potential and cytosolic calcium transients were optically mapped following an incremental pacing protocol. Calcium and action potential dynamics parameters were analyzed. VA vulnerability was assessed by electrically inducing ventricular fibrillations (VFs) in each heart. Western blot analysis was performed on LV tissues. Results Ibrutinib treatment resulted in higher vulnerability to VF in old SHR hearts (27.5 ± 7.5% vs. 5.7 ± 3.7%; p = 0.026) but not in young SHR hearts (8.0 ± 4.9% vs. 0%; p = 0.193). In old SHR hearts, following ibrutinib treatment, action potential duration (APD) alternans (p = 0.008) and APD alternans spatial discordance (p = 0.027) were more prominent. Moreover, calcium transient duration 50 was longer (p = 0.032), calcium amplitude alternans ratio was significantly lower (p = 0.001), and time-to-peak of calcium amplitude was shorter (p = 0.037). In young SHR hearts, there were no differences in calcium and APD dynamics. Conclusions Ibrutinib-induced VA is associated with old age in SHR. Acute dysregulation of calcium and repolarization dynamics play important roles in ibrutinib-induced VF.
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Key Words
- AF, atrial fibrillation
- AMPK, adenosine monophosphate-activated protein kinase
- APD, action potential duration
- CA, calcium alternans
- CaMKII, Ca2+/calmodulin-dependent protein kinase II
- CaT, calcium transient
- CaTD, calcium transient duration
- DAD, delayed afterdepolarization
- EAD, early afterpolarization
- LV, left ventricular
- PI3K, phosphoinositide 3-kinase
- PLB, phospholamban
- SCaE, spontaneous calcium elevation
- SHR, spontaneous hypertension rat
- SR, sarcoplasmic reticulum
- VA, ventricular arrhythmia
- VF, ventricular fibrillation
- action potential duration alternans
- calcium handling
- ibrutinib
- spatial discordant repolarization
- ventricular arrythmias
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Affiliation(s)
- Beibei Du
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada.,Department of Cardiology, The Third Hospital of Jilin University, Jilin Provincial Cardiovascular Research Institute, Changchun, China
| | - Praloy Chakraborty
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada
| | - Mohammed Ali Azam
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada
| | - Stéphane Massé
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada
| | - Patrick F H Lai
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada
| | - Ahmed Niri
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada
| | - Daoyuan Si
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada.,Department of Cardiology, The Third Hospital of Jilin University, Jilin Provincial Cardiovascular Research Institute, Changchun, China
| | - Paaladinesh Thavendiranathan
- Ted Rogers Program in Cardiotoxicity Prevention, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Husam Abdel-Qadir
- Ted Rogers Program in Cardiotoxicity Prevention, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Filio Billia
- Ted Rogers Program in Cardiotoxicity Prevention, Peter Munk Cardiac Center, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Kumaraswamy Nanthakumar
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada
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O'Shea C, Winter J, Holmes AP, Johnson DM, Correia JN, Kirchhof P, Fabritz L, Rajpoot K, Pavlovic D. Temporal irregularity quantification and mapping of optical action potentials using wave morphology similarity. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 157:84-93. [PMID: 31899215 PMCID: PMC7607254 DOI: 10.1016/j.pbiomolbio.2019.12.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/08/2019] [Accepted: 12/20/2019] [Indexed: 01/14/2023]
Abstract
BACKGROUND Cardiac optical mapping enables direct and high spatio-temporal resolution recording of action potential (AP) morphology. Temporal alterations in AP morphology are both predictive and consequent of arrhythmia. Here we sought to test if methods that quantify regularity of recorded waveforms could be applied to detect and quantify periods of temporal instability in optical mapping datasets in a semi-automated, user-unbiased manner. METHODS AND RESULTS We developed, tested and applied algorithms to quantify optical wave similarity (OWS) to study morphological temporal similarity of optically recorded APs. Unlike other measures (e.g. alternans ratio, beat-to-beat variability, arrhythmia scoring), the quantification of OWS is achieved without a restrictive definition of specific signal points/features and is instead derived by analysing the complete morphology from the entire AP waveform. Using model datasets, we validated the ability of OWS to measure changes in AP morphology, and tested OWS mapping in guinea pig hearts and mouse atria. OWS successfully detected and measured alterations in temporal regularity in response to several proarrhythmic stimuli, including alterations in pacing frequency, premature contractions, alternans and ventricular fibrillation. CONCLUSION OWS mapping provides an effective measure of temporal regularity that can be applied to optical datasets to detect and quantify temporal alterations in action potential morphology. This methodology provides a new metric for arrhythmia inducibility and scoring in optical mapping datasets.
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Affiliation(s)
- Christopher O'Shea
- Institute of Cardiovascular Sciences, University of Birmingham, UK; EPSRC Centre for Doctoral Training in Physical Sciences for Health, School of Chemistry, University of Birmingham, UK; School of Computer Science, University of Birmingham, Birmingham, B15 2TT, UK
| | - James Winter
- Institute of Cardiovascular Sciences, University of Birmingham, UK
| | - Andrew P Holmes
- Institute of Cardiovascular Sciences, University of Birmingham, UK; Institute of Clinical Sciences, University of Birmingham, UK
| | - Daniel M Johnson
- Institute of Cardiovascular Sciences, University of Birmingham, UK
| | - Joao N Correia
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, UK
| | - Paulus Kirchhof
- Institute of Cardiovascular Sciences, University of Birmingham, UK; Department of Cardiology, UHB NHS Foundation Trust, Birmingham, UK; Cardiology Specialty, SWBH NHS Trust, Birmingham, UK
| | - Larissa Fabritz
- Institute of Cardiovascular Sciences, University of Birmingham, UK; Department of Cardiology, UHB NHS Foundation Trust, Birmingham, UK
| | - Kashif Rajpoot
- School of Computer Science, University of Birmingham, Birmingham, B15 2TT, UK.
| | - Davor Pavlovic
- Institute of Cardiovascular Sciences, University of Birmingham, UK.
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Varró A, Tomek J, Nagy N, Virág L, Passini E, Rodriguez B, Baczkó I. Cardiac transmembrane ion channels and action potentials: cellular physiology and arrhythmogenic behavior. Physiol Rev 2020; 101:1083-1176. [PMID: 33118864 DOI: 10.1152/physrev.00024.2019] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cardiac arrhythmias are among the leading causes of mortality. They often arise from alterations in the electrophysiological properties of cardiac cells and their underlying ionic mechanisms. It is therefore critical to further unravel the pathophysiology of the ionic basis of human cardiac electrophysiology in health and disease. In the first part of this review, current knowledge on the differences in ion channel expression and properties of the ionic processes that determine the morphology and properties of cardiac action potentials and calcium dynamics from cardiomyocytes in different regions of the heart are described. Then the cellular mechanisms promoting arrhythmias in congenital or acquired conditions of ion channel function (electrical remodeling) are discussed. The focus is on human-relevant findings obtained with clinical, experimental, and computational studies, given that interspecies differences make the extrapolation from animal experiments to human clinical settings difficult. Deepening the understanding of the diverse pathophysiology of human cellular electrophysiology will help in developing novel and effective antiarrhythmic strategies for specific subpopulations and disease conditions.
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Affiliation(s)
- András Varró
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary.,MTA-SZTE Cardiovascular Pharmacology Research Group, Hungarian Academy of Sciences, Szeged, Hungary
| | - Jakub Tomek
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Norbert Nagy
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary.,MTA-SZTE Cardiovascular Pharmacology Research Group, Hungarian Academy of Sciences, Szeged, Hungary
| | - László Virág
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Elisa Passini
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Blanca Rodriguez
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - István Baczkó
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
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Watson SA, Dendorfer A, Thum T, Perbellini F. A practical guide for investigating cardiac physiology using living myocardial slices. Basic Res Cardiol 2020; 115:61. [PMID: 32914360 PMCID: PMC7496048 DOI: 10.1007/s00395-020-00822-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 08/10/2020] [Indexed: 12/22/2022]
Abstract
Ex vivo multicellular preparations are essential tools to study tissue physiology. Among them, the recent methodological and technological developments in living myocardial slices (LMS) are attracting increasing interest by the cardiac research field. Despite this, this research model remains poorly perceived and utilized by most research laboratories. Here, we provide a practical guide on how to use LMS to interrogate multiple aspects of cardiac function, structure and biochemistry. We discuss issues that should be considered to conduct successful experiments, including experimental design, sample preparation, data collection and analysis. We describe how laboratory setups can be adapted to accommodate and interrogate this multicellular research model. These adaptations can often be achieved at a reasonable cost with off-the-shelf components and operated reliably using well-established protocols and freely available software, which is essential to broaden the utilization of this method. We will also highlight how current measurements can be improved to further enhance data quality and reliability to ensure inter-laboratory reproducibility. Finally, we summarize the most promising biomedical applications and envision how living myocardial slices can lead to further breakthroughs.
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Affiliation(s)
| | - A Dendorfer
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany
| | - T Thum
- Institute of Molecular and Translational Therapeutic Strategies (IMTTS), Hannover Medical School, Hanover, Germany. .,National Heart and Lung Institute, Imperial College London, London, UK.
| | - F Perbellini
- Institute of Molecular and Translational Therapeutic Strategies (IMTTS), Hannover Medical School, Hanover, Germany.
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Myocardial Electrical Remodeling and the Arrhythmogenic Substrate in Hemorrhagic Shock-Induced Heart: Anti-Arrhythmogenic Effect of Liposome-Encapsulated Hemoglobin (HbV) on the Myocardium. Shock 2020; 52:378-386. [PMID: 30239419 DOI: 10.1097/shk.0000000000001262] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Prolonged low blood pressure <40 mmHg in hemorrhagic shock (HS) causes irreversible heart dysfunction, 'Shock Heart Syndrome' (SHS), which is associated with lethal arrhythmias (ventricular tachycardia or ventricular fibrillation [VT/VF]) leading to a poor prognosis. METHODS To investigate whether the liposome-encapsulated human hemoglobin oxygen carrier (HbV) is comparable in effectiveness to autologous washed red blood cells (wRBCs) for improving arrhythmogenic properties in SHS, optical mapping analysis (OMP), electrophysiological study (EPS), and pathological examinations were performed in Sprague-Dawley rat hearts obtained from rats subjected to acute HS by withdrawing 30% of total blood volume. After acute HS, the rats were immediately resuscitated by transfusing exactly the same amount of saline (SAL), 5% albumin (5% ALB), HbV, or wRBCs. After excising the heart, OMP and EPS were performed in Langendorff-perfused hearts. RESULTS OMP showed a tendency for abnormal conduction and significantly impaired action potential duration dispersion (APDd) in both ventricles with SAL and 5% ALB. In contrast, myocardial conduction and APDd were substantially preserved with HbV and wRBCs. Sustained VT/VF was easily provoked by a burst pacing stimulus to the left ventricle with SAL and 5% ALB. No VT/VF was induced with HbV and wRBCs. Pathology showed myocardial structural damage characterized by worse myocardial cell damage and Connexin43 with SAL and 5% ALB, whereas it was attenuated with HbV and wRBCs. CONCLUSIONS Ventricular structural remodeling after HS causes VT/VF in the presence of APDd. Transfusion of HbV prevents VT/VF, similarly to transfusion of wRBCs, by preventing electrical remodeling and preserving myocardial structures in HS-induced SHS.
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Liu T, Xiong F, Qi XY, Xiao J, Villeneuve L, Abu-Taha I, Dobrev D, Huang C, Nattel S. Altered calcium handling produces reentry-promoting action potential alternans in atrial fibrillation-remodeled hearts. JCI Insight 2020; 5:133754. [PMID: 32255765 DOI: 10.1172/jci.insight.133754] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 03/25/2020] [Indexed: 12/19/2022] Open
Abstract
Atrial fibrillation (AF) alters atrial cardiomyocyte (ACM) Ca2+ handling, promoting ectopic beat formation. We examined the effects of AF-associated remodeling on Ca2+-related action potential dynamics and consequences for AF susceptibility. AF was maintained electrically in dogs by right atrial (RA) tachypacing. ACMs isolated from AF dogs showed increased Ca2+ release refractoriness, spontaneous Ca2+ spark frequency, and cycle length (CL) threshold for Ca2+ and action potential duration (APD) alternans versus controls. AF increased the in situ CL threshold for Ca2+/APD alternans and spatial dispersion in Ca2+ release recovery kinetics, leading to spatially discordant alternans associated with reentrant rotor formation and susceptibility to AF induction/maintenance. The clinically available agent dantrolene reduced Ca2+ leak and CL threshold for Ca2+/APD alternans in ACMs and AF dog right atrium, while suppressing AF susceptibility; caffeine increased Ca2+ leak and CL threshold for Ca2+/APD alternans in control dog ACMs and RA tissues. In vivo, the atrial repolarization alternans CL threshold was increased in AF versus control, as was AF vulnerability. Intravenous dantrolene restored repolarization alternans threshold and reduced AF vulnerability. Immunoblots showed reduced expression of total and phosphorylated ryanodine receptors and calsequestrin in AF and unchanged phospholamban/SERCA expression. Thus, along with promoting spontaneous ectopy, AF-induced Ca2+ handling abnormalities favor AF by enhancing vulnerability to repolarization alternans, promoting initiation and maintenance of reentrant activity; dantrolene provides a lead molecule to target this mechanism.
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Affiliation(s)
- Tao Liu
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montréal, Québec, Canada.,Department of Cardiology, Renmin Hospital of Wuhan University, China.,Cardiovascular Research Institute, Wuhan University, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Feng Xiong
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montréal, Québec, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Xiao-Yan Qi
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Jiening Xiao
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Louis Villeneuve
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Issam Abu-Taha
- Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Germany
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Germany
| | - Congxin Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, China.,Cardiovascular Research Institute, Wuhan University, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Stanley Nattel
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montréal, Québec, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.,Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Germany.,IHU LIRYC Institute, Fondation Bordeaux Université, Bordeaux, France
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Cardiomyocyte calcium handling in health and disease: Insights from in vitro and in silico studies. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 157:54-75. [PMID: 32188566 DOI: 10.1016/j.pbiomolbio.2020.02.008] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/31/2019] [Accepted: 02/29/2020] [Indexed: 02/07/2023]
Abstract
Calcium (Ca2+) plays a central role in cardiomyocyte excitation-contraction coupling. To ensure an optimal electrical impulse propagation and cardiac contraction, Ca2+ levels are regulated by a variety of Ca2+-handling proteins. In turn, Ca2+ modulates numerous electrophysiological processes. Accordingly, Ca2+-handling abnormalities can promote cardiac arrhythmias via various mechanisms, including the promotion of afterdepolarizations, ion-channel modulation and structural remodeling. In the last 30 years, significant improvements have been made in the computational modeling of cardiomyocyte Ca2+ handling under physiological and pathological conditions. However, numerous questions involving the Ca2+-dependent regulation of different macromolecular complexes, cross-talk between Ca2+-dependent regulatory pathways operating over a wide range of time scales, and bidirectional interactions between electrophysiology and mechanics remain to be addressed by in vitro and in silico studies. A better understanding of disease-specific Ca2+-dependent proarrhythmic mechanisms may facilitate the development of improved therapeutic strategies. In this review, we describe the fundamental mechanisms of cardiomyocyte Ca2+ handling in health and disease, and provide an overview of currently available computational models for cardiomyocyte Ca2+ handling. Finally, we discuss important uncertainties and open questions about cardiomyocyte Ca2+ handling and highlight how synergy between in vitro and in silico studies may help to answer several of these issues.
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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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Swift LM, Burke M, Guerrelli D, Reilly M, Ramadan M, McCullough D, Prudencio T, Mulvany C, Chaluvadi A, Jaimes R, Posnack NG. Age-dependent changes in electrophysiology and calcium handling: implications for pediatric cardiac research. Am J Physiol Heart Circ Physiol 2019; 318:H354-H365. [PMID: 31886723 DOI: 10.1152/ajpheart.00521.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Rodent models are frequently employed in cardiovascular research, yet our understanding of pediatric cardiac physiology has largely been deduced from more simplified two-dimensional cell studies. Previous studies have shown that postnatal development includes an alteration in the expression of genes and proteins involved in cell coupling, ion channels, and intracellular calcium handling. Accordingly, we hypothesized that postnatal cell maturation is likely to lead to dynamic alterations in whole heart electrophysiology and calcium handling. To test this hypothesis, we employed multiparametric imaging and electrophysiological techniques to quantify developmental changes from neonate to adult. In vivo electrocardiograms were collected to assess changes in heart rate, variability, and atrioventricular conduction (Sprague-Dawley rats). Intact, whole hearts were transferred to a Langendorff-perfusion system for multiparametric imaging (voltage, calcium). Optical mapping was performed in conjunction with an electrophysiology study to assess cardiac dynamics throughout development. Postnatal age was associated with an increase in the heart rate (181 ± 34 vs. 429 ± 13 beats/min), faster atrioventricular conduction (94 ± 13 vs. 46 ± 3 ms), shortened action potentials (APD80: 113 ± 18 vs. 60 ± 17 ms), and decreased ventricular refractoriness (VERP: 157 ± 45 vs. 57 ± 14 ms; neonatal vs. adults, means ± SD, P < 0.05). Calcium handling matured with development, resulting in shortened calcium transient durations (168 ± 18 vs. 117 ± 14 ms) and decreased propensity for calcium transient alternans (160 ± 18- vs. 99 ± 11-ms cycle length threshold; neonatal vs. adults, mean ± SD, P < 0.05). Results of this study can serve as a comprehensive baseline for future studies focused on pediatric disease modeling and/or preclinical testing.NEW & NOTEWORTHY This is the first study to assess cardiac electrophysiology and calcium handling throughout postnatal development, using both in vivo and whole heart models.
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Affiliation(s)
- Luther M Swift
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia.,Children's National Heart Institute, Children's National Health System, Washington, District of Columbia
| | - Morgan Burke
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia.,Children's National Heart Institute, Children's National Health System, Washington, District of Columbia
| | - Devon Guerrelli
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia.,Children's National Heart Institute, Children's National Health System, Washington, District of Columbia
| | - Marissa Reilly
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia
| | - Manelle Ramadan
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia.,Children's National Heart Institute, Children's National Health System, Washington, District of Columbia
| | - Damon McCullough
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia.,Children's National Heart Institute, Children's National Health System, Washington, District of Columbia
| | - Tomas Prudencio
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia
| | - Colm Mulvany
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia
| | - Ashika Chaluvadi
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia
| | - Rafael Jaimes
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia.,Children's National Heart Institute, Children's National Health System, Washington, District of Columbia
| | - Nikki Gillum Posnack
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia.,Children's National Heart Institute, Children's National Health System, Washington, District of Columbia.,Department of Pediatrics and Department of Pharmacology and Physiology, School of Medicine and Health Sciences, George Washington University, Washington, District of Columbia
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Ijomone OM, Aluko OM, Okoh COA, Martins AC, Aschner M. Role for calcium signaling in manganese neurotoxicity. J Trace Elem Med Biol 2019; 56:146-155. [PMID: 31470248 DOI: 10.1016/j.jtemb.2019.08.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 08/15/2019] [Accepted: 08/16/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND Calcium is an essential macronutrient that is involved in many cellular processes. Homeostatic control of intracellular levels of calcium ions [Ca2+] is vital to maintaining cellular structure and function. Several signaling molecules are involved in regulating Ca2+ levels in cells and perturbation of calcium signaling processes is implicated in several neurodegenerative and neurologic conditions. Manganese [Mn] is a metal which is essential for basic physiological functions. However, overexposure to Mn from environmental contamination and workplace hazards is a global concern. Mn overexposure leads to its accumulation in several human organs particularly the brain. Mn accumulation in the brain results in a manganism, a Parkinsonian-like syndrome. Additionally, Mn is a risk factor for several neurodegenerative diseases including Parkinson's disease and Alzheimer's disease. Mn neurotoxicity also affects several neurotransmitter systems including dopaminergic, cholinergic and GABAergic. The mechanisms of Mn neurotoxicity are still being elucidated. AIM The review will highlight a potential role for calcium signaling molecules in the mechanisms of Mn neurotoxicity. CONCLUSION Ca2+ regulation influences the neurodegenerative process and there is possible role for perturbed calcium signaling in Mn neurotoxicity. Mechanisms implicated in Mn-induced neurodegeneration include oxidative stress, generation of free radicals, and apoptosis. These are influenced by mitochondrial integrity which can be dependent on intracellular Ca2+ homeostasis. Nevertheless, further elucidation of the direct effects of calcium signaling dysfunction and calcium-binding proteins activities in Mn neurotoxicity is required.
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Affiliation(s)
- Omamuyovwi M Ijomone
- The Neuro- Lab, Department of Human Anatomy, Federal University of Technology Akure, Ondo, Nigeria.
| | - Oritoke M Aluko
- Department of Physiology, Federal University of Technology Akure, Ondo, Nigeria
| | - Comfort O A Okoh
- The Neuro- Lab, Department of Human Anatomy, Federal University of Technology Akure, Ondo, Nigeria
| | - Airton Cunha Martins
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States.
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45
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Swift LM, Jaimes R, McCullough D, Burke M, Reilly M, Maeda T, Zhang H, Ishibashi N, Rogers JM, Posnack NG. Optocardiography and Electrophysiology Studies of Ex Vivo Langendorff-perfused Hearts. J Vis Exp 2019. [PMID: 31762469 DOI: 10.3791/60472] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Small animal models are most commonly used in cardiovascular research due to the availability of genetically modified species and lower cost compared to larger animals. Yet, larger mammals are better suited for translational research questions related to normal cardiac physiology, pathophysiology, and preclinical testing of therapeutic agents. To overcome the technical barriers associated with employing a larger animal model in cardiac research, we describe an approach to measure physiological parameters in an isolated, Langendorff-perfused piglet heart. This approach combines two powerful experimental tools to evaluate the state of the heart: electrophysiology (EP) study and simultaneous optical mapping of transmembrane voltage and intracellular calcium using parameter sensitive dyes (RH237, Rhod2-AM). The described methodologies are well suited for translational studies investigating the cardiac conduction system, alterations in action potential morphology, calcium handling, excitation-contraction coupling and the incidence of cardiac alternans or arrhythmias.
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Affiliation(s)
- Luther M Swift
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital
| | - Rafael Jaimes
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital
| | - Damon McCullough
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital
| | - Morgan Burke
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital
| | - Marissa Reilly
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital
| | - Takuya Maeda
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital; Center for Neuroscience Research, Children's National Hospital
| | - Hanyu Zhang
- Department of Biomedical Engineering, School of Engineering, University of Alabama at Birmingham
| | - Nobuyuki Ishibashi
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital; Center for Neuroscience Research, Children's National Hospital
| | - Jack M Rogers
- Department of Biomedical Engineering, School of Engineering, University of Alabama at Birmingham
| | - Nikki Gillum Posnack
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital; Department of Pediatrics, Department of Pharmacology & Physiology, School of Medicine and Health Sciences, George Washington University;
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46
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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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47
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Dong R, Mu-u-min R, Reith AJM, O’Shea C, He S, Duan K, Kou K, Grassam-Rowe A, Tan X, Pavlovic D, Ou X, Lei M. A Protocol for Dual Calcium-Voltage Optical Mapping in Murine Sinoatrial Preparation With Optogenetic Pacing. Front Physiol 2019; 10:954. [PMID: 31456689 PMCID: PMC6698704 DOI: 10.3389/fphys.2019.00954] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 07/09/2019] [Indexed: 01/08/2023] Open
Abstract
Among the animal models for studying the molecular basis of atrial and sinoatrial node (SAN) biology and disease, the mouse is a widely used species due to its feasibility for genetic modifications in genes encoding ion channels or calcium handling and signaling proteins in the heart. It is therefore highly valuable to develop robust methodologies for studying SAN and atrial electrophysiological function in this species. Here, we describe a protocol for performing dual calcium-voltage optical mapping on mouse sinoatrial preparation (SAP), in combination with an optogenetic approach, for studying SAP membrane potential, intracellular Ca2+ transients, and pacemaker activity. The protocol includes the details for preparing the intact SAP, robust tissue dual-dye loading, light-programmed pacing, and high-resolution optical mapping. Our protocol provides an example of use of the combination of optogenetic and optical mapping techniques for investigating SAP membrane potential and intracellular Ca2+ transients and pacemaker activity with high temporal and spatial resolution in specific cardiac tissues. Thus, our protocol provides a useful tool for studying SAP physiology and pathophysiology in mice.
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Affiliation(s)
- Ruirui Dong
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Razik Mu-u-min
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | | | - Christopher O’Shea
- Institute for Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Shicheng He
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Kaizhong Duan
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Kun Kou
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | | | - Xiaoqiu Tan
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Davor Pavlovic
- Institute for Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Xianhong Ou
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Ming Lei
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
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48
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O’Shea C, Holmes AP, Winter J, Correia J, Ou X, Dong R, He S, Kirchhof P, Fabritz L, Rajpoot K, Pavlovic D. Cardiac Optogenetics and Optical Mapping - Overcoming Spectral Congestion in All-Optical Cardiac Electrophysiology. Front Physiol 2019; 10:182. [PMID: 30899227 PMCID: PMC6416196 DOI: 10.3389/fphys.2019.00182] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Accepted: 02/14/2019] [Indexed: 12/30/2022] Open
Abstract
Optogenetic control of the heart is an emergent technology that offers unparalleled spatio-temporal control of cardiac dynamics via light-sensitive ion pumps and channels (opsins). This fast-evolving technique holds broad scope in both clinical and basic research setting. Combination of optogenetics with optical mapping of voltage or calcium fluorescent probes facilitates 'all-optical' electrophysiology, allowing precise optogenetic actuation of cardiac tissue with high spatio-temporal resolution imaging of action potential and calcium transient morphology and conduction patterns. In this review, we provide a synopsis of optogenetics and discuss in detail its use and compatibility with optical interrogation of cardiac electrophysiology. We briefly discuss the benefits of all-optical cardiac control and electrophysiological interrogation compared to traditional techniques, and describe mechanisms, unique features and limitations of optically induced cardiac control. In particular, we focus on state-of-the-art setup design, challenges in light delivery and filtering, and compatibility of opsins with fluorescent reporters used in optical mapping. The interaction of cardiac tissue with light, and physical and computational approaches to overcome the 'spectral congestion' that arises from the combination of optogenetics and optical mapping are discussed. Finally, we summarize recent preclinical work applications of combined cardiac optogenetics and optical mapping approach.
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Affiliation(s)
- Christopher O’Shea
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
- School of Computer Science, University of Birmingham, Birmingham, United Kingdom
- EPSRC Centre for Doctoral Training in Physical Sciences for Health, School of Chemistry, University of Birmingham, Birmingham, United Kingdom
| | - Andrew P. Holmes
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
- Institute of Clinical Sciences, University of Birmingham, Birmingham, United Kingdom
| | - James Winter
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Joao Correia
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Xianhong Ou
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease/Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Ruirui Dong
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease/Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Shicheng He
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease/Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Paulus Kirchhof
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
- Department of Cardiology, UHB NHS Trust, Birmingham, United Kingdom
| | - Larissa Fabritz
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
- Department of Cardiology, UHB NHS Trust, Birmingham, United Kingdom
| | - Kashif Rajpoot
- School of Computer Science, University of Birmingham, Birmingham, United Kingdom
| | - Davor Pavlovic
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
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O'Shea C, Holmes AP, Yu TY, Winter J, Wells SP, Correia J, Boukens BJ, De Groot JR, Chu GS, Li X, Ng GA, Kirchhof P, Fabritz L, Rajpoot K, Pavlovic D. ElectroMap: High-throughput open-source software for analysis and mapping of cardiac electrophysiology. Sci Rep 2019; 9:1389. [PMID: 30718782 PMCID: PMC6362081 DOI: 10.1038/s41598-018-38263-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 12/21/2018] [Indexed: 02/04/2023] Open
Abstract
The ability to record and analyse electrical behaviour across the heart using optical and electrode mapping has revolutionised cardiac research. However, wider uptake of these technologies is constrained by the lack of multi-functional and robustly characterised analysis and mapping software. We present ElectroMap, an adaptable, high-throughput, open-source software for processing, analysis and mapping of complex electrophysiology datasets from diverse experimental models and acquisition modalities. Key innovation is development of standalone module for quantification of conduction velocity, employing multiple methodologies, currently not widely available to researchers. ElectroMap has also been designed to support multiple methodologies for accurate calculation of activation, repolarisation, arrhythmia detection, calcium handling and beat-to-beat heterogeneity. ElectroMap implements automated signal segmentation, ensemble averaging and integrates optogenetic approaches. Here we employ ElectroMap for analysis, mapping and detection of pro-arrhythmic phenomena in silico, in cellulo, animal model and in vivo patient datasets. We anticipate that ElectroMap will accelerate innovative cardiac research and enhance the uptake, application and interpretation of mapping technologies leading to novel approaches for arrhythmia prevention.
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Affiliation(s)
- Christopher O'Shea
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- EPSRC Centre for Doctoral Training in Physical Sciences for Health, School of Chemistry, University of Birmingham, Birmingham, UK
- School of Computer Science, 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
| | - Ting Y Yu
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - James Winter
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Simon P Wells
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Department of Physiology, University of Melbourne, Melbourne, Australia
| | - Joao Correia
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Bastiaan J Boukens
- Amsterdam UMC, University of Amsterdam, Department of Anatomy and Physiology, Amsterdam, The Netherlands
| | - Joris R De Groot
- Amsterdam UMC, University of Amsterdam, Heart Center, Department of Cardiology, Amsterdam, The Netherlands
| | - Gavin S Chu
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, UK
| | - Xin Li
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - G Andre Ng
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, UK
| | - Paulus Kirchhof
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Department of Cardiology, UHB NHS Trust, Birmingham, UK
| | - Larissa Fabritz
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Department of Cardiology, UHB NHS Trust, 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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50
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Abstract
Voltage sensitive dyes (VSDs) are used for in vitro drug screening and for imaging of patterns of electrical activity in tissue. Wide application of this technology depends on the availability of sensors with high sensitivity (percent change of fluorescence per 100 mV), high fluorescence quantum yield, and fast response kinetics. A promising approach uses a two-component system consisting of anionic membrane permeable quenchers with fluorophores labeling one side of the membrane; this produces voltage-dependent fluorescence quenching. However, the quencher must be kept at low concentrations to minimize pharmacological effects, thus limiting sensitivity. By developing tethered bichromophoric fluorophore quencher (TBFQ) dyes, where the fluorophore and quencher are covalently connected by a long hydrophobic chain, the sensitivity is maximized and is independent of VSD concentration. A series of 13 TBFQ dyes based on the aminonaphthylethenylpyridinium (ANEP) fluorophore and the dipicrylamine anion (DPA) quencher have been synthesized and tested in an artificial lipid bilayer apparatus. The best of these, TBFQ1, shows a 2.5-fold change in fluorescence per 100 mV change in membrane potential, and the response kinetics is in the 10-20 ms range. This sensitivity is an order of magnitude better than that of commonly used VSDs. However, the fluorescence quantum yield is only 1.6%, which may make this first generation of TBFQ VSDs impractical for in vivo electrical imaging. Nevertheless, the design principles established here can serve as foundation for improved TBFQ VSDs. We believe this approach promises to greatly enhance our ability to monitor electrical activity in cells and tissues.
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Affiliation(s)
- Ping Yan
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, Connecticut 06030, United States
| | - Corey D. Acker
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, Connecticut 06030, United States
| | - Leslie M. Loew
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, Connecticut 06030, United States
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