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Roshanbinfar K, Schiffer M, Carls E, Angeloni M, Koleśnik-Gray M, Schruefer S, Schubert DW, Ferrazzi F, Krstić V, Fleischmann BK, Roell W, Engel FB. Electrically Conductive Collagen-PEDOT:PSS Hydrogel Prevents Post-Infarct Cardiac Arrhythmia and Supports hiPSC-Cardiomyocyte Function. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2403642. [PMID: 38653478 DOI: 10.1002/adma.202403642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Indexed: 04/25/2024]
Abstract
Myocardial infarction (MI) causes cell death, disrupts electrical activity, triggers arrhythmia, and results in heart failure, whereby 50-60% of MI-associated deaths manifest as sudden cardiac deaths (SCD). The most effective therapy for SCD prevention is implantable cardioverter defibrillators (ICDs). However, ICDs contribute to adverse remodeling and disease progression and do not prevent arrhythmia. This work develops an injectable collagen-PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) hydrogel that protects infarcted hearts against ventricular tachycardia (VT) and can be combined with human induced pluripotent stem cell (hiPSC)-cardiomyocytes to promote partial cardiac remuscularization. PEDOT:PSS improves collagen gel formation, micromorphology, and conductivity. hiPSC-cardiomyocytes in collagen-PEDOT:PSS hydrogels exhibit near-adult sarcomeric length, improved contractility, enhanced calcium handling, and conduction velocity. RNA-sequencing data indicate enhanced maturation and improved cell-matrix interactions. Injecting collagen-PEDOT:PSS hydrogels in infarcted mouse hearts decreases VT to the levels of healthy hearts. Collectively, collagen-PEDOT:PSS hydrogels offer a versatile platform for treating cardiac injuries.
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Affiliation(s)
- Kaveh Roshanbinfar
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054, Erlangen, Germany
| | - Miriam Schiffer
- Institute of Physiology I, Life and Brain Center, Medical Faculty, University of Bonn, Germany
| | - Esther Carls
- Department of Cardiac Surgery, UKB, University of Bonn, Germany
| | - Miriam Angeloni
- Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054, Erlangen, Germany
| | - Maria Koleśnik-Gray
- Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Staudtstr. 7, 91058, Erlangen, Germany
| | - Stefan Schruefer
- Institute of Polymer Materials, Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Martensstr. 7, 91058, Erlangen, Germany
| | - Dirk W Schubert
- Institute of Polymer Materials, Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Martensstr. 7, 91058, Erlangen, Germany
| | - Fulvia Ferrazzi
- Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054, Erlangen, Germany
- Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Muscle Research Center Erlangen (MURCE), 91054, Erlangen, Germany
| | - Vojislav Krstić
- Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Staudtstr. 7, 91058, Erlangen, Germany
| | - Bernd K Fleischmann
- Institute of Physiology I, Life and Brain Center, Medical Faculty, University of Bonn, Germany
| | - Wilhelm Roell
- Department of Cardiac Surgery, UKB, University of Bonn, Germany
| | - Felix B Engel
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054, Erlangen, Germany
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2
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Roshanbinfar K, Kolesnik-Gray M, Angeloni M, Schruefer S, Fiedler M, Schubert DW, Ferrazzi F, Krstic V, Engel FB. Collagen Hydrogel Containing Polyethylenimine-Gold Nanoparticles for Drug Release and Enhanced Beating Properties of Engineered Cardiac Tissues. Adv Healthc Mater 2023; 12:e2202408. [PMID: 36976709 DOI: 10.1002/adhm.202202408] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 03/10/2023] [Indexed: 03/29/2023]
Abstract
Cardiac tissue engineering is a promising strategy to prevent heart failure. However, several issues remain unsolved, including efficient electrical coupling and incorporating factors to enhance tissue maturation and vascularization. Herein, a biohybrid hydrogel that enhances beating properties of engineered cardiac tissues and allows drug release concurrently is developed. Gold nanoparticles (AuNPs) with different sizes (18-241 nm) and surface charges (33.9-55.4 mV) are synthesized by reducing gold (III) chloride trihydrate using branched polyethyleneimine (bPEI). These nanoparticles increase gel stiffness from ≈91 to ≈146 kPa, enhance electrical conductivity of collagen hydrogels from ≈40 to 49-68 mS cm-1 , and allow slow and steady release of loaded drugs. Engineered cardiac tissues based on bPEI-AuNP-collagen hydrogels and either primary or human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes show enhanced beating properties. hiPSC-derived cardiomyocytes exhibit more aligned and wider sarcomeres in bPEI-AuNP-collagen hydrogels compared to collagen hydrogels. Furthermore, the presence of bPEI-AuNPs result in advanced electrical coupling evidenced by synchronous and homogenous calcium flux throughout the tissue. RNA-seq analyses are in agreement with these observations. Collectively, this data demonstrate the potential of bPEI-AuNP-collagen hydrogels to improve tissue engineering approaches to prevent heart failure and possibly treat diseases of other electrically sensitive tissues.
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Affiliation(s)
- Kaveh Roshanbinfar
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, University of Erlangen-Nuremberg (FAU), Muscle Research Center Erlangen (MURCE), 91054, Erlangen, Germany
| | - Maria Kolesnik-Gray
- Department of Physics, University of Erlangen-Nuremberg (FAU), Staudtstr. 7, 91058, Erlangen, Germany
| | - Miriam Angeloni
- Institute of Pathology, University of Erlangen-Nuremberg (FAU), 91054, Erlangen, Germany
| | - Stefan Schruefer
- Institute of Polymer Materials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg, 91058, Erlangen, Germany
| | - Maren Fiedler
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, University of Erlangen-Nuremberg (FAU), Muscle Research Center Erlangen (MURCE), 91054, Erlangen, Germany
| | - Dirk W Schubert
- Institute of Polymer Materials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg, 91058, Erlangen, Germany
| | - Fulvia Ferrazzi
- Institute of Pathology, University of Erlangen-Nuremberg (FAU), 91054, Erlangen, Germany
- Department of Nephropathology, Institute of Pathology, University of Erlangen-Nuremberg (FAU), Muscle Research Center Erlangen (MURCE), 91054, Erlangen, Germany
| | - Vojislav Krstic
- Department of Physics, University of Erlangen-Nuremberg (FAU), Staudtstr. 7, 91058, Erlangen, Germany
| | - Felix B Engel
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, University of Erlangen-Nuremberg (FAU), Muscle Research Center Erlangen (MURCE), 91054, Erlangen, Germany
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3
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Xie A, Kang GJ, Kim EJ, Feng F, Givens SE, Ogle BM, Dudley SC. Lysosomal Ca 2+ flux modulates automaticity in ventricular cardiomyocytes and correlates with arrhythmic risk. PNAS NEXUS 2023; 2:pgad174. [PMID: 37303713 PMCID: PMC10255768 DOI: 10.1093/pnasnexus/pgad174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 05/16/2023] [Indexed: 06/13/2023]
Abstract
Automaticity involves Ca2+ handling at the cell membrane and sarcoplasmic reticulum (SR). Abnormal or acquired automaticity is thought to initiate ventricular arrhythmias associated with myocardial ischemia. Ca2+ flux from mitochondria can influence automaticity, and lysosomes also release Ca2+. Therefore, we tested whether lysosomal Ca2+ flux could influence automaticity. We studied ventricular human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), hiPSC 3D engineered heart tissues (EHTs), and ventricular cardiomyocytes isolated from infarcted mice. Preventing lysosomal Ca2+ cycling reduced automaticity in hiPSC-CMs. Consistent with a lysosomal role in automaticity, activating the transient receptor potential mucolipin channel (TRPML1) enhanced automaticity, and two channel antagonists reduced spontaneous activity. Activation or inhibition of lysosomal transcription factor EB (TFEB) increased or decreased total lysosomes and automaticity, respectively. In adult ischemic cardiomyocytes and hiPSC 3D EHTs, reducing lysosomal Ca2+ release also inhibited automaticity. Finally, TRPML1 was up-regulated in cardiomyopathic patients with ventricular tachycardia (VT) compared with those without VT. In summary, lysosomal Ca2+ handling modulates abnormal automaticity, and reducing lysosomal Ca2+ release may be a clinical strategy for preventing ventricular arrhythmias.
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Affiliation(s)
- An Xie
- Department of Medicine, University of Minnesota, 401 East River Parkway, VCRC 1st Floor, Suite 131, Minneapolis, MN 55455, USA
- Lillehei Heart Institute, University of Minnesota, 2231 6th Street SE, Suite 4-156, Minneapolis, MN 55455, USA
| | - Gyeoung-Jin Kang
- Department of Medicine, University of Minnesota, 401 East River Parkway, VCRC 1st Floor, Suite 131, Minneapolis, MN 55455, USA
- Lillehei Heart Institute, University of Minnesota, 2231 6th Street SE, Suite 4-156, Minneapolis, MN 55455, USA
| | - Eun Ji Kim
- Department of Medicine, University of Minnesota, 401 East River Parkway, VCRC 1st Floor, Suite 131, Minneapolis, MN 55455, USA
- Lillehei Heart Institute, University of Minnesota, 2231 6th Street SE, Suite 4-156, Minneapolis, MN 55455, USA
| | - Feng Feng
- Department of Medicine, University of Minnesota, 401 East River Parkway, VCRC 1st Floor, Suite 131, Minneapolis, MN 55455, USA
- Lillehei Heart Institute, University of Minnesota, 2231 6th Street SE, Suite 4-156, Minneapolis, MN 55455, USA
| | - Sophie E Givens
- Department of Biomedical Engineering, Stem Cell Institute, University of Minnesota, McGuire Translational Research Facility, 2001 6th Street SE, Mail Code 2873, Minneapolis, MN 55455, USA
| | - Brenda M Ogle
- Lillehei Heart Institute, University of Minnesota, 2231 6th Street SE, Suite 4-156, Minneapolis, MN 55455, USA
- Department of Biomedical Engineering, Stem Cell Institute, University of Minnesota, McGuire Translational Research Facility, 2001 6th Street SE, Mail Code 2873, Minneapolis, MN 55455, USA
- Department of Pediatrics, Institute for Engineering in Medicine, University of Minnesota, 420 Delaware Street Southeast, 725 Mayo Memorial Building, MMC 94, Minneapolis, MN 55455, USA
| | - Samuel C Dudley
- Department of Medicine, University of Minnesota, 401 East River Parkway, VCRC 1st Floor, Suite 131, Minneapolis, MN 55455, USA
- Lillehei Heart Institute, University of Minnesota, 2231 6th Street SE, Suite 4-156, Minneapolis, MN 55455, USA
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4
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Pereira CH, Bare DJ, Rosas PC, Dias FAL, Banach K. The role of P21-activated kinase (Pak1) in sinus node function. J Mol Cell Cardiol 2023; 179:90-101. [PMID: 37086972 PMCID: PMC10294268 DOI: 10.1016/j.yjmcc.2023.04.004] [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: 08/25/2022] [Revised: 04/11/2023] [Accepted: 04/11/2023] [Indexed: 04/24/2023]
Abstract
Sinoatrial node (SAN) dysfunction (SND) and atrial arrhythmia frequently occur simultaneously with a hazard ratio of 4.2 for new onset atrial fibrillation (AF) in SND patients. In the atrial muscle attenuated activity of p21-activated kinase 1 (Pak1) increases the risk for AF by enhancing NADPH oxidase 2 dependent production of reactive oxygen species (ROS). However, the role of Pak1 dependent ROS regulation in SAN function has not yet been determined. We hypothesize that Pak1 activity maintains SAN activity by regulating the expression of the hyperpolarization activated cyclic nucleotide gated cation channel (HCN). To determine Pak1 dependent changes in heart rate (HR) regulation we quantified the intrinsic sinus rhythm in wild type (WT) and Pak1 deficient (Pak1-/-) mice of both sexes in vivo and in isolated Langendorff perfused hearts. Pak1-/- hearts displayed an attenuated HR in vivo after autonomic blockage and in isolated hearts. The contribution of the Ca2+ clock to pacemaker activity remained unchanged, but Ivabradine (3 μM), a blocker of HCN channels that are a membrane clock component, eliminated the differences in SAN activity between WT and Pak1-/- hearts. Reduced HCN4 expression was confirmed in Pak1-/- right atria. The reduced HCN activity in Pak1-/- could be rescued by class II HDAC inhibition (LMK235), ROS scavenging (TEMPOL) or attenuation of Extracellular Signal-Regulated Kinase (ERK) 1/2 activity (SCH772984). No sex specific differences in Pak1 dependent SAN regulation were determined. Our results establish Pak1 as a class II HDAC regulator and a potential therapeutic target to attenuate SAN bradycardia and AF susceptibility.
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Affiliation(s)
- Carlos H Pereira
- Dept. of Internal Medicine/Cardiology, Rush University Medical Center, 1750 W. Harrison St., Chicago, IL 60612, USA; Biological Science Center, Department of Physiology, Av. Cel Francisco H. dos Santos 100, 19031 Centro Politécnico-Curitiba, Brazil.
| | - Dan J Bare
- Dept. of Physiology & Biophysics, The Ohio State University, 5018 Graves Hall, 333 W.10th Ave., Columbus, OH 4321, USA.
| | - Paola C Rosas
- Dept. of Pharmacy Practice, College of Pharmacy, 833 S Wood St., Chicago, IL 60612, USA.
| | - Fernando A L Dias
- Biological Science Center, Department of Physiology, Av. Cel Francisco H. dos Santos 100, 19031 Centro Politécnico-Curitiba, Brazil.
| | - Kathrin Banach
- Dept. of Internal Medicine/Cardiology, Rush University Medical Center, 1750 W. Harrison St., Chicago, IL 60612, USA.
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5
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Varma D, Almeida JFQ, DeSantiago J, Blatter LA, Banach K. Inositol 1,4,5-trisphosphate receptor - reactive oxygen signaling domain regulates excitation-contraction coupling in atrial myocytes. J Mol Cell Cardiol 2022; 163:147-155. [PMID: 34755642 PMCID: PMC8826595 DOI: 10.1016/j.yjmcc.2021.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 09/03/2021] [Accepted: 10/13/2021] [Indexed: 02/03/2023]
Abstract
The inositol 1,4,5-trisphosphate receptor (InsP3R) is up-regulated in patients with atrial fibrillation (AF) and InsP3-induced Ca2+ release (IICR) is linked to pro-arrhythmic spontaneous Ca2+ release events. Nevertheless, knowledge of the physiological relevance and regulation of InsP3Rs in atrial muscle is still limited. We hypothesize that InsP3R and NADPH oxidase 2 (NOX2) form a functional signaling domain where NOX2 derived reactive oxygen species (ROS) regulate InsP3R agonist affinity and thereby Ca2+ release. To quantitate the contribution of IICR to atrial excitation-contraction coupling (ECC) atrial myocytes (AMs) were isolated from wild type and NOX2 deficient (Nox2-/-) mice and changes in the cytoplasmic Ca2+ concentration ([Ca2+]i; fluo-4/AM, indo-1) or ROS (2',7'-dichlorofluorescein, DCF) were monitored by fluorescence microscopy. Superfusion of AMs with Angiotensin II (AngII: 1 μmol/L) significantly increased diastolic [Ca2+]i (F/F0, Ctrl: 1.00 ± 0.01, AngII: 1.20 ± 0.03; n = 7; p < 0.05), the field stimulation induced Ca2+ transient (CaT) amplitude (ΔF/F0, Ctrl: 2.00 ± 0.17, AngII: 2.39 ± 0.22, n = 7; p < 0.05), and let to the occurrence of spontaneous increases in [Ca2+]i. These changes in [Ca2+]i were suppressed by the InsP3R blocker 2-aminoethoxydiphenyl-borate (2-APB; 1 μmol/L). Concomitantly, AngII induced an increase in ROS production that was sensitive to the NOX2 specific inhibitor gp91ds-tat (1 μmol/L). In NOX2-/- AMs, AngII failed to increase diastolic [Ca2+]i, CaT amplitude, and the frequency of spontaneous Ca2+ increases. Furthermore, the enhancement of CaTs by exposure to membrane permeant InsP3 was abolished by NOX inhibition with apocynin (1 μM). AngII induced IICR in Nox2-/- AMs could be restored by addition of exogenous ROS (tert-butyl hydroperoxide, tBHP: 5 μmol/L). In saponin permeabilized AMs InsP3 (5 μmol/L) induced Ca2+ sparks that increased in frequency in the presence of ROS (InsP3: 9.65 ± 1.44 sparks*s-1*(100μm)-1; InsP3 + tBHP: 10.77 ± 1.5 sparks*s-1*(100μm)-1; n = 5; p < 0.05). The combined effect of InsP3 + tBHP was entirely suppressed by 2-APB and Xestospongine C (XeC). Changes in IICR due to InsP3R glutathionylation induced by diamide could be reversed by the reducing agent dithiothreitol (DTT: 1 mmol/L) and prevented by pretreatment with 2-APB, supporting that the ROS-dependent post-translational modification of the InsP3R plays a role in the regulation of ECC. Our data demonstrate that in AMs the InsP3R is under dual control of agonist induced InsP3 and ROS formation and suggest that InsP3 and NOX2-derived ROS co-regulate atrial IICR and ECC in a defined InsP3R/NOX2 signaling domain.
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Affiliation(s)
- Disha Varma
- Dept. of Internal Medicine/Cardiology, Rush University Medical Center, 1750 W. Harrison St, Chicago, IL 60612, USA.
| | - Jonathas F Q Almeida
- Dept. of Internal Medicine/Cardiology, Rush University Medical Center, 1750 W. Harrison St, Chicago, IL 60612, USA.
| | - Jaime DeSantiago
- Dept. of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison St, Chicago, IL 60612, USA.
| | - Lothar A Blatter
- Dept. of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison St, Chicago, IL 60612, USA.
| | - Kathrin Banach
- Dept. of Internal Medicine/Cardiology, Rush University Medical Center, 1750 W. Harrison St, Chicago, IL 60612, USA.
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6
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Blatter LA, Kanaporis G, Martinez-Hernandez E, Oropeza-Almazan Y, Banach K. Excitation-contraction coupling and calcium release in atrial muscle. Pflugers Arch 2021; 473:317-329. [PMID: 33398498 DOI: 10.1007/s00424-020-02506-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/03/2020] [Accepted: 12/16/2020] [Indexed: 01/02/2023]
Abstract
In cardiac muscle, the process of excitation-contraction coupling (ECC) describes the chain of events that links action potential induced myocyte membrane depolarization, surface membrane ion channel activation, triggering of Ca2+ induced Ca2+ release from the sarcoplasmic reticulum (SR) Ca2+ store to activation of the contractile machinery that is ultimately responsible for the pump function of the heart. Here we review similarities and differences of structural and functional attributes of ECC between atrial and ventricular tissue. We explore a novel "fire-diffuse-uptake-fire" paradigm of atrial ECC and Ca2+ release that assigns a novel role to the SR SERCA pump and involves a concerted "tandem" activation of the ryanodine receptor Ca2+ release channel by cytosolic and luminal Ca2+. We discuss the contribution of the inositol 1,4,5-trisphosphate (IP3) receptor Ca2+ release channel as an auxiliary pathway to Ca2+ signaling, and we review IP3 receptor-induced Ca2+ release involvement in beat-to-beat ECC, nuclear Ca2+ signaling, and arrhythmogenesis. Finally, we explore the topic of electromechanical and Ca2+ alternans and its ramifications for atrial arrhythmia.
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Affiliation(s)
- L A Blatter
- Department of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison Street, Chicago, IL, 60612, USA.
| | - G Kanaporis
- Department of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison Street, Chicago, IL, 60612, USA
| | - E Martinez-Hernandez
- Department of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison Street, Chicago, IL, 60612, USA
| | - Y Oropeza-Almazan
- Department of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison Street, Chicago, IL, 60612, USA
| | - K Banach
- Department of Internal Medicine/Cardiology, Rush University Medical Center, Chicago, IL, 60612, USA
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7
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Burton RAB, Terrar DA. Emerging Evidence for cAMP-calcium Cross Talk in Heart Atrial Nanodomains Where IP 3-Evoked Calcium Release Stimulates Adenylyl Cyclases. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2021; 4:25152564211008341. [PMID: 37366374 PMCID: PMC10243587 DOI: 10.1177/25152564211008341] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/01/2021] [Accepted: 03/07/2021] [Indexed: 06/28/2023]
Abstract
Calcium handling is vital to normal physiological function in the heart. Human atrial arrhythmias, eg. atrial fibrillation, are a major morbidity and mortality burden, yet major gaps remain in our understanding of how calcium signaling pathways function and interact. Inositol trisphosphate (IP3) is a calcium-mobilizing second messenger and its agonist-induced effects have been observed in many tissue types. In the atria IP3 receptors (IR3Rs) residing on junctional sarcoplasmic reticulum augment cellular calcium transients and, when over-stimulated, lead to arrhythmogenesis. Recent studies have demonstrated that the predominant pathway for IP3 actions in atrial myocytes depends on stimulation of calcium-dependent forms of adenylyl cyclase (AC8 and AC1) by IP3-evoked calcium release from the sarcoplasmic reticulum. AC8 shows co-localisation with IP3Rs and AC1 appears to be nearby. These observations support crosstalk between calcium and cAMP pathways in nanodomains in atria. Similar mechanisms also appear to operate in the pacemaker region of the sinoatrial node. Here we discuss these significant advances in our understanding of atrial physiology and pathology, together with implications for the identification of potential novel targets and modulators for the treatment of atrial arrhythmias.
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Affiliation(s)
| | - Derek A. Terrar
- Department of Pharmacology, University of Oxford, Oxford, UK
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8
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Luo X, Li W, Künzel K, Henze S, Cyganek L, Strano A, Poetsch MS, Schubert M, Guan K. IP3R-Mediated Compensatory Mechanism for Calcium Handling in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes With Cardiac Ryanodine Receptor Deficiency. Front Cell Dev Biol 2020; 8:772. [PMID: 32903370 PMCID: PMC7434870 DOI: 10.3389/fcell.2020.00772] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 07/22/2020] [Indexed: 02/03/2023] Open
Abstract
In adult cardiomyocytes (CMs), the type 2 ryanodine receptor (RYR2) is an indispensable Ca2+ release channel that ensures the integrity of excitation-contraction coupling, which is fundamental for every heartbeat. However, the role and importance of RYR2 during human embryonic cardiac development are still poorly understood. Here, we generated two human induced pluripotent stem cell (iPSC)-based RYR2 knockout (RYR2–/–) lines using the CRISPR/Cas9 gene editing technology. We found that RYR2–/–-iPSCs could differentiate into CMs with the efficiency similar to control-iPSCs (Ctrl-iPSCs); however, the survival of iPSC-CMs was markedly affected by the lack of functional RYR2. While Ctrl-iPSC-CMs exhibited regular Ca2+ handling, we observed significantly reduced frequency and intense abnormalities of Ca2+ transients in RYR2–/–-iPSC-CMs. Ctrl-iPSC-CMs displayed sensitivity to extracellular Ca2+ ([Ca2+ ]o) and caffeine in a concentration-dependent manner, while RYR2–/–-iPSC-CMs showed inconsistent reactions to [Ca2+ ]o and were insensitive to caffeine, indicating there is no RYR2-mediated Ca2+ release from the sarcoplasmic reticulum (SR). Instead, compensatory mechanism for calcium handling in RYR2–/–-iPSC-CMs is partially mediated by the inositol 1,4,5-trisphosphate receptor (IP3R). Similar to Ctrl-iPSC-CMs, SR Ca2+ refilling in RYR2–/–-iPSC-CMs is mediated by SERCA. Additionally, RYR2–/–-iPSC-CMs showed a decreased beating rate and a reduced peak amplitude of L-type Ca2+ current. These findings demonstrate that RYR2 is not required for CM lineage commitment but is important for CM survival and contractile function. IP3R-mediated Ca2+ release is one of the major compensatory mechanisms for Ca2+ cycling in human CMs with the RYR2 deficiency.
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Affiliation(s)
- Xiaojing Luo
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany
| | - Wener Li
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany
| | - Karolina Künzel
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany
| | - Sarah Henze
- Clinic for Cardiology and Pneumology, Universitätsmedizin Göttingen, Göttingen, Germany
| | - Lukas Cyganek
- Clinic for Cardiology and Pneumology, Universitätsmedizin Göttingen, Göttingen, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - Anna Strano
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany
| | - Mareike S Poetsch
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany
| | - Mario Schubert
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany
| | - Kaomei Guan
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany.,Clinic for Cardiology and Pneumology, Universitätsmedizin Göttingen, Göttingen, Germany
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9
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Yue X, Hazan A, Lotteau S, Zhang R, Torrente AG, Philipson KD, Ottolia M, Goldhaber JI. Na/Ca exchange in the atrium: Role in sinoatrial node pacemaking and excitation-contraction coupling. Cell Calcium 2020; 87:102167. [PMID: 32028091 DOI: 10.1016/j.ceca.2020.102167] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 01/21/2020] [Indexed: 01/14/2023]
Abstract
Na/Ca exchange is the dominant calcium (Ca) efflux mechanism in cardiac myocytes. Although our knowledge of exchanger function (NCX1 in the heart) was originally established using biochemical and electrophysiological tools such as cardiac sarcolemmal vesicles and the giant patch technique [1-4], many advances in our understanding of the physiological/pathophysiological roles of NCX1 in the heart have been obtained using a suite of genetically modified mice. Early mouse studies focused on modification of expression levels of NCX1 in the ventricles, with transgenic overexpressors, global NCX1 knockout (KO) mice (which were embryonic lethal if homozygous), and finally ventricular-specific NCX1 KO [5-12]. We found, to our surprise, that ventricular cardiomyocytes lacking NCX1 can survive and function by engaging a clever set of adaptations to minimize Ca entry, while maintaining contractile function through an increase in excitation-contraction (EC) coupling gain [5,6,13]. Having studied ventricular NCX1 ablation in detail, we more recently focused on elucidating the role of NCX1 in the atria through altering NCX1 expression. Using a novel atrial-specific NCX1 KO mouse, we found unexpected changes in atrial cell morphology and calcium handling, together with dramatic alterations in the function of sinoatrial node (SAN) pacemaker activity. In this review, we will discuss these findings and their implications for cardiac disease.
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Affiliation(s)
- Xin Yue
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Adina Hazan
- Smidt Heart Institute, Department of Cardiology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Sabine Lotteau
- Smidt Heart Institute, Department of Cardiology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Rui Zhang
- Smidt Heart Institute, Department of Cardiology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Angelo G Torrente
- Institute for Functional Genomics, University of Montpellier, CNRS, INSERM, Montpellier, France
| | | | - Michela Ottolia
- Department of Anesthesiology and Perioperative Medicine, Division of Molecular Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Joshua I Goldhaber
- Smidt Heart Institute, Department of Cardiology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
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10
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Structural and Mechanistic Bases of Nuclear Calcium Signaling in Human Pluripotent Stem Cell-Derived Ventricular Cardiomyocytes. Stem Cells Int 2019; 2019:8765752. [PMID: 31065282 PMCID: PMC6466844 DOI: 10.1155/2019/8765752] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 12/10/2018] [Accepted: 01/08/2019] [Indexed: 11/23/2022] Open
Abstract
The loss of nonregenerative, terminally differentiated cardiomyocytes (CMs) due to aging or diseases is generally considered irreversible. Human pluripotent stem cells (hPSCs) can self-renew while maintaining their pluripotency to differentiate into all cell types, including ventricular (V) cardiomyocytes (CMs), to provide a potential unlimited ex vivo source of CMs for heart disease modeling, drug/cardiotoxicity screening, and cell-based therapies. In the human heart, cytosolic Ca2+ signals are well characterized but the contribution of nuclear Ca2+ is essentially unexplored. The present study investigated nuclear Ca2+ signaling in hPSC-VCMs. Calcium transient or sparks in hPSC-VCMs were measured by line scanning using a spinning disc confocal microscope. We observed that nuclear Ca2+, which stems from unitary sparks due to the diffusion of cytosolic Ca2+ that are mediated by RyRs on the nuclear reticulum, is functional. Parvalbumin- (PV-) mediated Ca2+ buffering successfully manipulated Ca2+ transient and stimuli-induced apoptosis in hPSC-VCMs. We also investigated the effect of Ca2+ on gene transcription in hPSC-VCMs, and the involvement of nuclear factor of activated T-cell (NFAT) pathway was identified. The overexpression of Ca2+-sensitive, nuclear localized Ca2+/calmodulin-dependent protein kinase II δB (CaMKIIδB) induced cardiac hypertrophy through nuclear Ca2+/CaMKIIδB/HDAC4/MEF2 pathway. These findings provide insights into nuclear Ca2+ signal in hPSC-VCMs, which may lead to novel strategies for maturation as well as improved systems for disease modeling, drug discovery, and cell-based therapies.
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Meng XL, Chen CL, Liu YY, Su SJ, Gou JM, Huan FN, Wang D, Liu HS, Ben SB, Lu J. Selenoprotein SELENOK Enhances the Migration and Phagocytosis of Microglial Cells by Increasing the Cytosolic Free Ca 2+ Level Resulted from the Up-Regulation of IP 3R. Neuroscience 2019; 406:38-49. [PMID: 30849448 DOI: 10.1016/j.neuroscience.2019.02.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 02/23/2019] [Accepted: 02/25/2019] [Indexed: 01/14/2023]
Abstract
Enhancing the migration and phagocytosis of microglial cells is of great significance for the reducing of the risk of the neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD). The effect of mouse selenoprotein K (mSELENOK) on the migration and phagocytosis of BV2 microglial cells and its mechanism were studied. The results showed that the over-expression of mSELENOK can increase the migratory and phagocytic abilities of the microglial cells, while the knockdown of mSELENOK can decrease the migratory and phagocytic abilities of the cells. The cytosolic free Ca2+ level and inositol trisphosphate receptor (IP3R) mRNA transcript and protein expression were also increased significantly as the consequence of the over-expression of mSELENOK in the microglial cells. On the contrary, the level of cytosolic free Ca2+ and the mRNA transcript and protein expression of IP3R in mSELENOK knockdown cells were decreased significantly. 2-aminoethoxydiphenyl borate (2-APB), an antagonist of IP3R, could prevent the increased migration, phagocytosis, and cytosolic free Ca2+ level of mSELENOK over-expressed microglial cells, and knockdown of IP3R3 could reduce the increased cytosolic Ca2+ level in mSELENOK over-expressed microglial cells. Further studies revealed that selenium supplement (Na2SeO3) can increase the expression of mSELENOK in microglial cells significantly. In summary, these data suggest that mSELENOK can increase cytosolic free Ca2+ level of microglial cells by up-regulating the expression of IP3R, thus enhancing the migration and phagocytosis of microglial cells. Our results indicated that mSELENOK is an important selenoprotein, which plays a role in trace element selenium's functions and can enhance the migration and phagocytosis of microglial cells.
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Affiliation(s)
- Xue-Lian Meng
- School of Pharmaceutical Science, Liaoning University, Shenyang, China; Research Center for Natural product pharmacy of Liaoning Province, Shenyang, China
| | - Chang-Lan Chen
- School of Pharmaceutical Science, Liaoning University, Shenyang, China; Research Center for Natural product pharmacy of Liaoning Province, Shenyang, China.
| | - Ying-Ying Liu
- School of Pharmaceutical Science, Liaoning University, Shenyang, China
| | - Shu-Jie Su
- School of Pharmaceutical Science, Liaoning University, Shenyang, China
| | - Jiang-Min Gou
- School of Pharmaceutical Science, Liaoning University, Shenyang, China
| | - Feng-Ning Huan
- School of Pharmaceutical Science, Liaoning University, Shenyang, China
| | - Dan Wang
- School of Pharmaceutical Science, Liaoning University, Shenyang, China; Research Center for Natural product pharmacy of Liaoning Province, Shenyang, China
| | - Hong-Sheng Liu
- Research Center for Computer Simulating and Information Processing of Bio-macromolecules of Liaoning Province, Shenyang, China
| | - Song-Bin Ben
- School of Life Science, Liaoning University, Shenyang, China
| | - Jing Lu
- School of Pharmaceutical Science, Liaoning University, Shenyang, China; Research Center for Natural product pharmacy of Liaoning Province, Shenyang, China.
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12
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Xie A, Zhou A, Liu H, Shi G, Liu M, Boheler KR, Dudley SC. Mitochondrial Ca2+ flux modulates spontaneous electrical activity in ventricular cardiomyocytes. PLoS One 2018; 13:e0200448. [PMID: 30001390 PMCID: PMC6042741 DOI: 10.1371/journal.pone.0200448] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Accepted: 06/26/2018] [Indexed: 11/23/2022] Open
Abstract
Introduction Ca2+ release from sarcoplasmic reticulum (SR) is known to contribute to automaticity via the cytoplasmic Na+-Ca2+ exchanger (NCX). Mitochondria participate in Ca2+ cycling. We studied the role of mitochondrial Ca2+ flux in ventricular spontaneous electrical activity. Methods Spontaneously contracting mouse embryonic stem cells (ESC)-derived ventricular cardiomyocytes (CMs) were differentiated from wild type and ryanodine receptor type 2 (RYR2) knockout mouse ESCs and differentiated for 19–21 days. Automaticity was also observed in human induced pluripotent stem cell (hiPSC)-derived ventricular CMs differentiated for 30 days, and acute isolated adult mouse ventricular cells in ischemic simulated buffer. Action potentials (APs) were recorded by perforated whole cell current-clamp. Cytoplasmic and mitochondrial Ca2+ transients were determined by fluorescent imaging. Results In mouse ESC-derived ventricular CMs, spontaneous beating was dependent on the L-type Ca2+ channel, cytoplasmic NCX and mitochondrial NCX. Spontaneous beating was modulated by SR Ca2+ release from RYR2 or inositol trisphosphate receptors (IP3R), the pacemaker current (If) and mitochondrial Ca2+ uptake by the mitochondrial Ca2+ uniporter (MCU). In RYR2 knockout mouse ESC-derived ventricular CMs, mitochondrial Ca2+ flux influenced spontaneous beating independently of the SR Ca2+ release from RYR2, and the mitochondrial effect was dependent on IP3R SR Ca2+ release. Depolarization of mitochondria and preservation of ATP could terminate spontaneous beating. A contribution of mitochondrial Ca2+ flux to automaticity was confirmed in hiPSC-derived ventricular CMs and ischemic adult mouse ventricular CMs, confirming the findings across species and cell maturity levels. Conclusions Mitochondrial and sarcolemma NCX fluxes are required for ventricular automaticity. Mitochondrial Ca2+ uptake plays a modulatory role. Mitochondrial Ca2+ uptake through MCU is influenced by IP3R-dependent SR Ca2+ release.
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Affiliation(s)
- An Xie
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, United States of America
| | - Anyu Zhou
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, United States of America
| | - Hong Liu
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, United States of America
| | - Guangbin Shi
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, United States of America
| | - Man Liu
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, United States of America
| | - Kenneth R. Boheler
- Stem Cell and Regenerative Medicine Consortium, LKS Faculty of Medicine, Hong Kong University, Hong Kong, P.R. China
| | - Samuel C. Dudley
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, United States of America
- * E-mail:
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13
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Xie A, Song Z, Liu H, Zhou A, Shi G, Wang Q, Gu L, Liu M, Xie LH, Qu Z, Dudley SC. Mitochondrial Ca 2+ Influx Contributes to Arrhythmic Risk in Nonischemic Cardiomyopathy. J Am Heart Assoc 2018; 7:e007805. [PMID: 29627768 PMCID: PMC6015427 DOI: 10.1161/jaha.117.007805] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 03/07/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Heart failure (HF) is associated with increased arrhythmia risk and triggered activity. Abnormal Ca2+ handling is thought to underlie triggered activity, and mitochondria participate in Ca2+ homeostasis. METHODS AND RESULTS A model of nonischemic HF was induced in C57BL/6 mice by hypertension. Computer simulations were performed using a mouse ventricular myocyte model of HF. Isoproterenol-induced premature ventricular contractions and ventricular fibrillation were more prevalent in nonischemic HF mice than sham controls. Isolated myopathic myocytes showed decreased cytoplasmic Ca2+ transients, increased mitochondrial Ca2+ transients, and increased action potential duration at 90% repolarization. The alteration of action potential duration at 90% repolarization was consistent with in vivo corrected QT prolongation and could be explained by augmented L-type Ca2+ currents, increased Na+-Ca2+ exchange currents, and decreased total K+ currents. Of myopathic ventricular myocytes, 66% showed early afterdepolarizations (EADs) compared with 17% of sham myocytes (P<0.05). Intracellular application of 1 μmol/L Ru360, a mitochondrial Ca2+ uniporter-specific antagonist, could reduce mitochondrial Ca2+ transients, decrease action potential duration at 90% repolarization, and ameliorate EADs. Furthermore, genetic knockdown of mitochondrial Ca2+ uniporters inhibited mitochondrial Ca2+ uptake, reduced Na+-Ca2+ exchange currents, decreased action potential duration at 90% repolarization, suppressed EADs, and reduced ventricular fibrillation in nonischemic HF mice. Computer simulations showed that EADs promoted by HF remodeling could be abolished by blocking either the mitochondrial Ca2+ uniporter or the L-type Ca2+ current, consistent with the experimental observations. CONCLUSIONS Mitochondrial Ca2+ handling plays an important role in EADs seen with nonischemic cardiomyopathy and may represent a therapeutic target to reduce arrhythmic risk in this condition.
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Affiliation(s)
- An Xie
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN
| | - Zhen Song
- Department of Medicine, David Geffen School of Medicine at University of California, Los Angeles, CA
| | - Hong Liu
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN
| | - Anyu Zhou
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN
| | - Guangbin Shi
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN
| | - Qiongying Wang
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN
| | - Lianzhi Gu
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN
| | - Man Liu
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN
| | - Lai-Hua Xie
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School Rutgers, The State University of New Jersey, Newark, NJ
| | - Zhilin Qu
- Department of Medicine, David Geffen School of Medicine at University of California, Los Angeles, CA
| | - Samuel C Dudley
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN
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14
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Kim HS, Yoon JW, Li H, Jeong GO, Park JJ, Shin SE, Jang IH, Kim JH, Park WS. Functional expression and pharmaceutical efficacy of cardiac-specific ion channels in human embryonic stem cell-derived cardiomyocytes. Sci Rep 2017; 7:13821. [PMID: 29062050 PMCID: PMC5653792 DOI: 10.1038/s41598-017-14198-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/21/2017] [Indexed: 01/08/2023] Open
Abstract
Cardiomyocytes differentiated from human pluripotent stem cells provide promising tools for screening of cardiotoxic drugs. For evaluation of human pluripotent stem cell-derived cardiomyocytes for cardiotoxicity test, in the present study, human embryonic stem cells (hESCs) were differentiated to cardiomyocytes, followed by metabolic selection to enrich the differentiated cardiomyocytes. The highly purified hESC-derived cardiomyocytes (hESC-CMs) expressed several cardiomyocyte-specific markers including cTnT, MLC2a, and α-SA, but not pluripotency markers, such as OCT4 and NANOG. Patch clamp technique and RT-PCR revealed the expression of cardiomyocyte-specific Na+, Ca2+, and K+ channels and cardiac action potential in hESC-CMs. To explore the potential use of hESC-CMs as functional cardiomyocytes for drug discovery and cardiotoxicity screening, we examined the effects of bisindolylmaleimide (BIM) (I), which inhibits native cardiac Ca2+ channels, on the Ca2+ channel activity of hESC-CMs. We observed a similar response for the BIM (I)-induced modulation of Ca2+ channels between hESC-CMs and native cardiomyocytes through L-type Ca2+ channel current. These results suggest that hESC-CMs can be useful for evaluation of pharmaceutical efficacy and safety of novel drug candidate in cardiac research.
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Affiliation(s)
- Han Sol Kim
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, 24341, Republic of Korea
| | - Jung Won Yoon
- Department of Physiology, School of Medicine, Pusan National University, Yangsan, 50612, Republic of Korea
| | - Hongliang Li
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, 24341, Republic of Korea
| | - Geun Ok Jeong
- Department of Physiology, School of Medicine, Pusan National University, Yangsan, 50612, Republic of Korea
| | - Jin Ju Park
- Department of Physiology, School of Medicine, Pusan National University, Yangsan, 50612, Republic of Korea
| | - Sung Eun Shin
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, 24341, Republic of Korea
| | - Il Ho Jang
- Department of Oral Biochemistry and Molecular Biology, Pusan National University School of Dentistry, Yangsan, 50612, Republic of Korea
| | - Jae Ho Kim
- Department of Physiology, School of Medicine, Pusan National University, Yangsan, 50612, Republic of Korea. .,Research Institute of Convergence Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, 50612, Republic of Korea.
| | - Won Sun Park
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, 24341, Republic of Korea.
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15
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Role of Nitric Oxide, Nitric Oxide Synthase, Soluble Guanylyl Cyclase, and cGMP-Dependent Protein Kinase I in Mouse Stem Cell Cardiac Development. Stem Cells Int 2016; 2016:2868323. [PMID: 27840646 PMCID: PMC5093303 DOI: 10.1155/2016/2868323] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 09/26/2016] [Indexed: 11/17/2022] Open
Abstract
Introduction and Aim. Nitric oxide (NO) can trigger cardiac differentiation of embryonic stem cells (ESCs), indicating a cardiogenic function of the NO synthetizing enzyme(s) (NOS). However, the involvement of the NO/NOS downstream effectors soluble guanylyl cyclase (sGC) and cGMP activated protein kinase I (PKG-I) is less defined. Therefore, we assess the involvement of the entire NO/NOS/sGC/PKG-I pathway during cardiac differentiation process. Methods. Mouse ESCs were differentiated toward cardiac lineages by hanging drop methodology for 21 days. NOS/sGC/PKG-I pathway was studied quantifying genes, proteins, enzymatic activities, and effects of inhibition during differentiation. Percentages of beating embryoid bodies (mEBs) were evaluated as an index of cardiogenesis. Results and Discussion. Genes and protein expression of enzymes were increased during differentiation with distinctive kinetics and proteins possessed their enzymatic functions. Exogenous administered NO accelerated whereas the blockade of PKG-I strongly slowed cardiogenesis. sGC inhibition was effective only at early stages and NOS blockade ineffective. Of NOS/sGC/PKG-I pathway, PKG-I seems to play the prominent role in cardiac maturation. Conclusion. We concluded that exogenous administered NO and other pharmacological strategies able to increase the activity of PKG-I provide new tools to investigate and promote differentiation of cardiogenic precursors.
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16
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Wei W, Huang W, Yue J. Requirement of IP3 receptor 3 (IP3R3) in nitric oxide induced cardiomyocyte differentiation of mouse embryonic stem cells. Exp Cell Res 2016; 346:9-16. [PMID: 27349290 DOI: 10.1016/j.yexcr.2016.06.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 06/21/2016] [Accepted: 06/23/2016] [Indexed: 01/29/2023]
Abstract
Nitric oxide (NO) markedly induces cardiomyocyte (CM) differentiation of embryonic stem (ES) cells. Here we examined the role of the Ca(2+) signaling in the NO-induced CM differentiation of mouse ES cells. We found that NO induced intracellular Ca(2+) increases in ES cells in a dose-dependent manner, and application of IP3 pathway antagonists not only significantly inhibited this induced Ca(2+) increase but also abolished NO-induced CM differentiation of ES cells. Subsequently, all 3 types of inositol 1, 4, 5-trisphosphate (IP3) receptors (IP3Rs) in mouse ES cells were individually or triply knocked down. Interestingly, only knockdown of type 3 IP3R (IP3R3) or triple-knockdown of three types of IP3Rs significantly inhibited the NO-induced Ca(2+) increases. Consistently, IP3R3 knockdown blocked the NO-induced CM differentiation of ES cells. CMs derived from IP3R3 knockdown ES cells also showed both structural and functional defects. In summary, our results indicate that the IP3R3-Ca(2+) pathway is required for NO-induced CM differentiation of ES cells.
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Affiliation(s)
- Wenjie Wei
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China; Department of Biology, South University of Science and Technology of China, Shenzhen 518052, China
| | - Wei Huang
- Department of Biology, South University of Science and Technology of China, Shenzhen 518052, China
| | - Jianbo Yue
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China.
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17
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Youm JB. Electrophysiological properties and calcium handling of embryonic stem cell-derived cardiomyocytes. Integr Med Res 2016; 5:3-10. [PMID: 28462091 PMCID: PMC5381424 DOI: 10.1016/j.imr.2015.12.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Revised: 12/28/2015] [Accepted: 12/30/2015] [Indexed: 01/31/2023] Open
Abstract
Embryonic stem cell-derived cardiomyocytes (ESC-CMs) hold great interest in many fields of research including clinical applications such as stem cell and gene therapy for cardiac repair or regeneration. ESC-CMs are also used as a platform tool for pharmacological tests or for investigations of cardiac remodeling. ESC-CMs have many different aspects of morphology, electrophysiology, calcium handling, and bioenergetics compared with adult cardiomyocytes. They are immature in morphology, similar to sinus nodal-like in the electrophysiology, higher contribution of trans-sarcolemmal Ca2+ influx to Ca2+ handling, and higher dependence on anaerobic glycolysis. Here, I review a detailed electrophysiology and Ca2+ handling features of ESC-CMs during differentiation into adult cardiomyocytes to gain insights into how all the developmental changes are related to each other to display cardinal features of developing cardiomyocytes.
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Affiliation(s)
- Jae Boum Youm
- National Research Laboratory for Mitochondrial Signaling Laboratory, Department of Physiology, College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University, Busan, Korea
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18
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The Interaction between Adult Cardiac Fibroblasts and Embryonic Stem Cell-Derived Cardiomyocytes Leads to Proarrhythmic Changes in In Vitro Cocultures. Stem Cells Int 2016; 2016:2936126. [PMID: 26880949 PMCID: PMC4736407 DOI: 10.1155/2016/2936126] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 11/16/2015] [Accepted: 12/14/2015] [Indexed: 01/14/2023] Open
Abstract
Transplantation of stem cell-derived cardiomyocytes is one of the most promising therapeutic approaches after myocardial infarction, as loss of cardiomyocytes is virtually irreversible by endogenous repair mechanisms. In myocardial scars, transplanted cardiomyocytes will be in immediate contact with cardiac fibroblasts. While it is well documented how the electrophysiology of neonatal cardiomyocytes is modulated by cardiac fibroblasts of the same developmental stage, it is unknown how adult cardiac fibroblasts (aCFs) affect the function of embryonic stem cell-derived cardiomyocytes (ESC-CMs). To investigate the effects of aCFs on ESC-CM electrophysiology, we performed extra- and intracellular recordings of murine aCF-ESC-CM cocultures. We observed that spontaneous beating behaviour was highly irregular in aCF-ESC-CM cocultures compared to cocultures with mesenchymal stem cells (coefficient of variation of the interspike interval: 40.5 ± 15.2% versus 9.3 ± 2.0%, p = 0.008) and that action potential amplitude and maximal upstroke velocity (V max) were reduced (amplitude: 52.3 ± 1.7 mV versus 65.1 ± 1.5 mV, V max: 7.0 ± 1.0 V/s versus 36.5 ± 5.3 V/s), while action potential duration (APD) was prolonged (APD50: 25.6 ± 1.0 ms versus 16.8 ± 1.9 ms, p < 0.001; APD90: 52.2 ± 1.5 ms versus 43.3 ± 3.3 ms, p < 0.01) compared to controls. Similar changes could be induced by aCF-conditioned medium. We conclude that the presence of aCFs changes automaticity and induces potentially proarrhythmic changes of ESC-CM electrophysiology.
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19
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Zhang XH, Morad M. Calcium signaling in human stem cell-derived cardiomyocytes: Evidence from normal subjects and CPVT afflicted patients. Cell Calcium 2015; 59:98-107. [PMID: 26725479 DOI: 10.1016/j.ceca.2015.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 12/10/2015] [Accepted: 12/11/2015] [Indexed: 10/22/2022]
Abstract
Derivation of cardiomyocyte cell lines from human fibroblasts (induced pluripotent stem cells, iPSCs) has made it possible not only to investigate the electrophysiological and Ca(2+) signaling properties of these cells, but also to determine the altered electrophysiological and Ca(2+)-signaling profiles of such cells lines derived from patients expressing mutation-inducing pathologies. This approach has the potential of generating in vitro human models of cardiovascular diseases where cellular pathology can be investigated in detail and possibly specific pharmacotherapy developed. Although this approach has been applied to a number of mutations in channel proteins that cause arrhythmias, there are only few detailed reports addressing Ca(2+) signaling pathologies beyond measurements of Ca(2+) transients in intact non-voltage clamped cells. Unfortunately, full understanding of Ca(2+) signaling pathologies remains elusive, not only because of the plethora of Ca(2+) signaling proteins defects that cause arrhythmias and cardiomyopathies, but also because detailed functional properties of Ca(2+) signaling proteins are difficult to obtain. Catecholaminergic polymorphic ventricular tachycardia (CPVT1) is a malignant inherited arrhythmogenic disorder predominantly caused by mutations in the cardiac ryanodine receptor (RyR2). Thus far over 150 mutations in RyR2 have been identified that appear to cause this arrhythmia, a number of which have been expressed and studied in transgenic mice or cell-line models. The development of human iPSC-technology makes it possible to create human heart cell-lines carrying these mutations, making detailed identification of Ca(2+) signaling defects and its specific pharmacotherapy possible. In this review we shall first briefly summarize the essential characteristics of the mammalian cardiac Ca(2+) signaling, then compare them to Ca(2+) signaling phenotypes of human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CM) and to those of rat neonatal cardiomyocytes, and categorize the possible variance in Ca(2+) signaling defects caused by different CPVT-inducing mutations as expressed in hiPSC-CMs.
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Affiliation(s)
- Xiao-Hua Zhang
- Cardiac Signaling Center of USC, MUSC, & Clemson University, Charleston, SC 29425, USA
| | - Martin Morad
- Cardiac Signaling Center of USC, MUSC, & Clemson University, Charleston, SC 29425, USA.
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20
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Kane C, Couch L, Terracciano CMN. Excitation-contraction coupling of human induced pluripotent stem cell-derived cardiomyocytes. Front Cell Dev Biol 2015; 3:59. [PMID: 26484342 PMCID: PMC4586503 DOI: 10.3389/fcell.2015.00059] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 09/11/2015] [Indexed: 01/17/2023] Open
Abstract
Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) hold enormous potential in many fields of cardiovascular research. Overcoming many of the limitations of their embryonic counterparts, the application of iPSC-CMs ranges from facilitating investigation of familial cardiac disease and pharmacological toxicity screening to personalized medicine and autologous cardiac cell therapies. The main factor preventing the full realization of this potential is the limited maturity of iPSC-CMs, which display a number of substantial differences in comparison to adult cardiomyocytes. Excitation–contraction (EC) coupling, a fundamental property of cardiomyocytes, is often described in iPSC-CMs as being more analogous to neonatal than adult cardiomyocytes. With Ca2+ handling linked, directly or indirectly, to almost all other properties of cardiomyocytes, a solid understanding of this process will be crucial to fully realizing the potential of this technology. Here, we discuss the implications of differences in EC coupling when considering the potential applications of human iPSC-CMs in a number of areas as well as detailing the current understanding of this fundamental process in these cells.
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Affiliation(s)
- Christopher Kane
- Laboratory of Cell Electrophysiology, National Heart and Lung Institute, Imperial College London London, UK
| | - Liam Couch
- Laboratory of Cell Electrophysiology, National Heart and Lung Institute, Imperial College London London, UK
| | - Cesare M N Terracciano
- Laboratory of Cell Electrophysiology, National Heart and Lung Institute, Imperial College London London, UK
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21
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Kapoor N, Tran A, Kang J, Zhang R, Philipson KD, Goldhaber JI. Regulation of calcium clock-mediated pacemaking by inositol-1,4,5-trisphosphate receptors in mouse sinoatrial nodal cells. J Physiol 2015; 593:2649-63. [PMID: 25903031 DOI: 10.1113/jp270082] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 04/15/2015] [Indexed: 01/30/2023] Open
Abstract
KEY POINTS Inositol-1,4,5-trisphosphate receptors (IP3 Rs) modulate pacemaking in embryonic heart, but their role in adult sinoatrial node (SAN) pacemaking is uncertain. We found that stimulation of IP3 Rs accelerates spontaneous pacing rate in isolated mouse SAN cells, whereas inhibition of IP3 Rs slows pacing. In atrial-specific sodium-calcium exchanger (NCX) knockout (KO) SAN cells, where the Ca(2+) clock is uncoupled from the membrane clock, IP3 R agonists and antagonists modulate the rate of spontaneous Ca(2+) waves, suggesting that IP3 R-mediated Ca(2+) release modulates the Ca(2+) clock. IP3 R modulation also regulates Ca(2+) spark parameters, a reflection of ryanodine receptor open probability, consistent with the effect of IP3 signalling on Ca(2+) clock frequency. Modulation of Ca(2+) clock frequency by IP3 signalling in NCX KO SAN cells demonstrates that the effect is independent of NCX. These findings support development of IP3 signalling modulators for regulation of heart rate, particularly in heart failure where IP3 Rs are upregulated. ABSTRACT Cardiac pacemaking initiated by the sinus node is attributable to the interplay of several membrane currents. These include the depolarizing 'funny current' (If ) and the sodium-calcium exchanger current (INCX ). The latter is activated by ryanodine receptor (RyR)-mediated calcium (Ca(2+) ) release from the sarcoplasmic reticulum (SR). Another SR Ca(2+) release channel, the inositol-1,4,5-triphosphate receptor (IP3 R), has been implicated in the generation of spontaneous Ca(2+) release in atrial and ventricular cardiomyocytes. Whether IP3 R-mediated Ca(2+) release also influences SAN automaticity is controversial, in part due to the confounding influence of periodic Ca(2+) flux through the sarcolemma accompanying each beat. We took advantage of atrial-specific sodium-calcium exchanger (NCX) knockout (KO) SAN cells to study the influence of IP3 signalling on cardiac pacemaking in a system where periodic intracellular Ca(2+) cycling persists despite the absence of depolarization or Ca(2+) flux across the sarcolemma. We recorded confocal line scans of spontaneous Ca(2+) release in WT and NCX KO SAN cells in the presence or absence of an IP3 R blocker (2-aminoethoxydiphenyl borate, 2-APB), or during block of IP3 production by the phospholipase C inhibitor U73122. 2-APB and U73122 decreased the frequency of spontaneous Ca(2+) transients and waves in WT and NCX KO cells, respectively. Alternatively, increased IP3 production induced by phenylephrine increased Ca(2+) transient and wave frequency. We conclude that IP3 R-mediated SR Ca(2+) flux is crucial for initiating and modulating the RyR-mediated Ca(2+) cycling that regulates SAN pacemaking. Our results in NCX KO SAN cells also demonstrate that RyRs, but not NCX, are required for IP3 to modulate Ca(2+) clock frequency.
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Affiliation(s)
- Nidhi Kapoor
- Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Andrew Tran
- Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Jeanney Kang
- Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Rui Zhang
- Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Kenneth D Philipson
- Department of Physiology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, USA
| | - Joshua I Goldhaber
- Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
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22
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Marcu IC, Illaste A, Heuking P, Jaconi ME, Ullrich ND. Functional Characterization and Comparison of Intercellular Communication in Stem Cell-Derived Cardiomyocytes. Stem Cells 2015; 33:2208-18. [PMID: 25968594 DOI: 10.1002/stem.2009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 03/08/2015] [Indexed: 02/05/2023]
Abstract
One novel treatment strategy for the diseased heart focuses on the use of pluripotent stem cell-derived cardiomyocytes (SC-CMs) to overcome the heart's innate deficiency for self-repair. However, targeted application of SC-CMs requires in-depth characterization of their true cardiogenic potential in terms of excitability and intercellular coupling at cellular level and in multicellular preparations. In this study, we elucidated the electrical characteristics of single SC-CMs and intercellular coupling quality of cell pairs, and concomitantly compared them with well-characterized murine native neonatal and immortalized HL-1 cardiomyocytes. Firstly, we investigated the electrical properties and Ca(2+) signaling mechanisms specific to cardiac contraction in single SC-CMs. Despite heterogeneity of the new cardiac cell population, their electrophysiological activity and Ca(2+) handling were similar to native cells. Secondly, we investigated the capability of paired SC-CMs to form an adequate subunit of a functional syncytium and analyzed gap junctions and signal transmission by dye transfer in cell pairs. We discovered significantly diminished coupling in SC-CMs compared with native cells, which could not be enhanced by a coculture approach combining SC-CMs and primary CMs. Moreover, quantitative and structural analysis of gap junctions presented significantly reduced connexin expression levels compared with native CMs. Strong dependence of intercellular coupling on gap junction density was further confirmed by computational simulations. These novel findings demonstrate that despite the cardiogenic electrophysiological profile, SC-CMs present significant limitations in intercellular communication. Inadequate coupling may severely impair functional integration and signal transmission, which needs to be carefully considered for the prospective use of SC-CMs in cardiac repair. Stem Cells 2015;33:2208-2218.
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Affiliation(s)
- Irene C Marcu
- Department of Physiology, University of Bern, Bern, Switzerland.,Department of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Ardo Illaste
- Department of Physiology, University of Bern, Bern, Switzerland
| | - Pernilla Heuking
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Marisa E Jaconi
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Nina D Ullrich
- Department of Physiology, University of Bern, Bern, Switzerland.,Department of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
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Louch WE, Koivumäki JT, Tavi P. Calcium signalling in developing cardiomyocytes: implications for model systems and disease. J Physiol 2015; 593:1047-63. [PMID: 25641733 PMCID: PMC4358669 DOI: 10.1113/jphysiol.2014.274712] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Accepted: 12/28/2014] [Indexed: 12/15/2022] Open
Abstract
Adult cardiomyocytes exhibit complex Ca(2+) homeostasis, enabling tight control of contraction and relaxation. This intricate regulatory system develops gradually, with progressive maturation of specialized structures and increasing capacity of Ca(2+) sources and sinks. In this review, we outline current understanding of these developmental processes, and draw parallels to pathophysiological conditions where cardiomyocytes exhibit a striking regression to an immature state of Ca(2+) homeostasis. We further highlight the importance of understanding developmental physiology when employing immature cardiomyocyte models such as cultured neonatal cells and stem cells.
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Affiliation(s)
- William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo0424, Oslo, Norway
- K. G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo0316, Oslo, Norway
| | - Jussi T Koivumäki
- Simula Research Laboratory, Center for Cardiological Innovation and Center for Biomedical ComputingOslo, Norway
| | - Pasi Tavi
- Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern FinlandKuopio, Finland
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24
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Beiert T, Bruegmann T, Sasse P. Optogenetic activation of Gq signalling modulates pacemaker activity of cardiomyocytes. Cardiovasc Res 2014; 102:507-16. [PMID: 24576953 DOI: 10.1093/cvr/cvu046] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS Investigation of Gq signalling with pharmacological agonists of Gq-coupled receptors lacks spatio-temporal precision. The aim of this study was to establish melanopsin, a light-sensitive Gq-coupled receptor, as a new tool for the investigation of spatial and temporal effects of Gq stimulation on pacemaking in cardiomyocytes at an early developmental stage. METHODS AND RESULTS A vector for ubiquitous expression of melanopsin was tested in HEK293FT cells, which showed light-induced production of inositol-1,4,5-trisphosphate and elevation of intracellular Ca(2+) concentration. Mouse embryonic stem cells were stably transfected with this plasmid and differentiated into spontaneously beating embryoid bodies (EBs). Cardiomyocytes within EBs showed melanopsin expression and illumination (60 s, 308.5 nW/mm(2), 470 nm) of EBs increased beating rate within 10.2 ± 1.7 s to 317.1 ± 16.3% of baseline frequency. Illumination as short as 5 s was sufficient for generating the maximal frequency response. After termination of illumination, baseline frequency was reached with a decay constant of 27.1 ± 2.5 s. The light-induced acceleration of beating frequency showed a sigmoid dependence on light intensity with a half maximal effective light intensity of 41.7 nW/mm(2). Interestingly, EBs showed a high rate of irregular contractions after termination of high-intensity illumination. Local Gq activation by illumination of a small region in a functional syncytium of cardiomyocytes led to pacemaker activity within the illuminated area. CONCLUSIONS Light-induced Gq activation in melanopsin-expressing cardiomyocytes increases beating rate and generates local pacemaker activity. We propose that melanopsin is a powerful optogenetic tool for the investigation of spatial and temporal aspects of Gq signalling in cardiovascular research.
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Affiliation(s)
- Thomas Beiert
- Institute of Physiology I, Life & Brain Center, University of Bonn, Sigmund-Freud-Strasse 25, Bonn 53105, Germany
| | - Tobias Bruegmann
- Institute of Physiology I, Life & Brain Center, University of Bonn, Sigmund-Freud-Strasse 25, Bonn 53105, Germany
| | - Philipp Sasse
- Institute of Physiology I, Life & Brain Center, University of Bonn, Sigmund-Freud-Strasse 25, Bonn 53105, Germany
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25
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DeSantiago J, Bare DJ, Xiao L, Ke Y, Solaro RJ, Banach K. p21-Activated kinase1 (Pak1) is a negative regulator of NADPH-oxidase 2 in ventricular myocytes. J Mol Cell Cardiol 2014; 67:77-85. [PMID: 24380729 PMCID: PMC3930036 DOI: 10.1016/j.yjmcc.2013.12.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 12/19/2013] [Accepted: 12/21/2013] [Indexed: 12/20/2022]
Abstract
Ischemic conditions reduce the activity of the p21-activated kinase (Pak1) resulting in increased arrhythmic activity. Triggered arrhythmic activity during ischemia is based on changes in cellular ionic balance and the cells Ca(2+) handling properties. In the current study we used isolated mouse ventricular myocytes (VMs) deficient for the expression of Pak1 (Pak1(-/-)) to determine the mechanism by which Pak1 influences the generation of arrhythmic activity during simulated ischemia. The Ca(2+) transient amplitude and kinetics did not significantly change in wild type (WT) and Pak1(-/-) VMs during 15 min of simulated ischemia. However, Pak1(-/-) VMs exhibited an exaggerated increase in [Ca(2+)]i, which resulted in spontaneous Ca(2+) release events and waves. The Ca(2+) overload in Pak1(-/-) VMs could be suppressed with a reverse mode blocker (KB-R7943) of the sodium calcium exchanger (NCX), a cytoplasmic scavenger of reactive oxygen species (ROS; TEMPOL) or a RAC1 inhibitor (NSC23766). Measurements of the cytoplasmic ROS levels revealed that decreased Pak1 activity in Pak1(-/-) VMs or VMs treated with the Pak1 inhibitor (IPA3) enhanced cellular ROS production. The Pak1 dependent increase in ROS was attenuated in VMs deficient for NADPH oxidase 2 (NOX2; p47(phox-/-)) or in VMs where NOX2 was inhibited (gp91ds-tat). Voltage clamp recordings showed increased NCX activity in Pak1(-/-) VMs that depended on enhanced NOX2 induced ROS production. The exaggerated Ca(2+) overload in Pak1(-/-) VMs could be mimicked by low concentrations of ouabain. Overall our data show that Pak1 is a critical negative regulator of NOX2 dependent ROS production and that a latent ROS dependent stimulation of NCX activity can predispose VMs to Ca(2+) overload under conditions where no significant changes in excitation-contraction coupling are yet evident.
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Affiliation(s)
- Jaime DeSantiago
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA; Department of Medicine, Section of Cardiology, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
| | - Dan J Bare
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA; Department of Medicine, Section of Cardiology, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
| | - Lei Xiao
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA; Department of Medicine, Section of Cardiology, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA; Pulmonary, Critical Care, Sleep and Allergy, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
| | - Yunbo Ke
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA; Department of Physiology and Biophysics, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
| | - R John Solaro
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA; Department of Physiology and Biophysics, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
| | - Kathrin Banach
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA; Department of Medicine, Section of Cardiology, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA.
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26
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Karppinen S, Rapila R, Mäkikallio K, Hänninen SL, Rysä J, Vuolteenaho O, Tavi P. Endothelin-1 signalling controls early embryonic heart rate in vitro and in vivo. Acta Physiol (Oxf) 2014; 210:369-80. [PMID: 24325624 DOI: 10.1111/apha.12194] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 04/10/2013] [Accepted: 01/11/2013] [Indexed: 12/13/2022]
Abstract
AIM Spontaneous activity of embryonic cardiomyocytes originates from sarcoplasmic reticulum (SR) Ca(2+) release during early cardiogenesis. However, the regulation of heart rate during embryonic development is still not clear. The aim of this study was to determine how endothelin-1 (ET-1) affects the heart rate of embryonic mice, as well as the pathway through which it exerts its effects. METHODS The effects of ET-1 and ET-1 receptor inhibition on cardiac contraction were studied using confocal Ca(2+) imaging of isolated mouse embryonic ventricular cardiomyocytes and ultrasonographic examination of embryonic cardiac contractions in utero. In addition, the amount of ET-1 peptide and ET receptor a (ETa) and b (ETb) mRNA levels were measured during different stages of development of the cardiac muscle. RESULTS High ET-1 concentration and expression of both ETa and ETb receptors was observed in early cardiac tissue. ET-1 was found to increase the frequency of spontaneous Ca(2+) oscillations in E10.5 embryonic cardiomyocytes in vitro. Non-specific inhibition of ET receptors with tezosentan caused arrhythmia and bradycardia in isolated embryonic cardiomyocytes and in whole embryonic hearts both in vitro (E10.5) and in utero (E12.5). ET-1-mediated stimulation of early heart rate was found to occur via ETb receptors and subsequent inositol trisphosphate receptor activation and increased SR Ca(2+) leak. CONCLUSION Endothelin-1 is required to maintain a sufficient heart rate, as well as to prevent arrhythmia during early development of the mouse heart. This is achieved through ETb receptor, which stimulates Ca(2+) leak through IP3 receptors.
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Affiliation(s)
- S. Karppinen
- Department of Biotechnology and Molecular Medicine; A.I. Virtanen Institute for Molecular Sciences; University of Eastern Finland; Kuopio Finland
| | - R. Rapila
- Department of Biotechnology and Molecular Medicine; A.I. Virtanen Institute for Molecular Sciences; University of Eastern Finland; Kuopio Finland
| | - K. Mäkikallio
- Department of Obstetrics and Gynecology; University of Oulu; Oulu Finland
| | - S. L. Hänninen
- Department of Physiology; Institute of Biomedicine; University of Oulu; Oulu Finland
| | - J. Rysä
- Department of Pharmacology and Toxicology; Institute of Biomedicine; University of Oulu; Oulu Finland
| | - O. Vuolteenaho
- Department of Physiology; Institute of Biomedicine; University of Oulu; Oulu Finland
| | - P. Tavi
- Department of Biotechnology and Molecular Medicine; A.I. Virtanen Institute for Molecular Sciences; University of Eastern Finland; Kuopio Finland
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27
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Barile L, Altomare C, Zaza A. Induced pluripotent stem cells: progress towards a biomedical application. Expert Rev Cardiovasc Ther 2014; 9:1265-9. [DOI: 10.1586/erc.11.123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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28
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Kapoor N, Maxwell JT, Mignery GA, Will D, Blatter LA, Banach K. Spatially defined InsP3-mediated signaling in embryonic stem cell-derived cardiomyocytes. PLoS One 2014; 9:e83715. [PMID: 24409283 PMCID: PMC3883750 DOI: 10.1371/journal.pone.0083715] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 11/06/2013] [Indexed: 11/19/2022] Open
Abstract
The functional role of inositol 1,4,5-trisphosphate (InsP3) signaling in cardiomyocytes is not entirely understood but it was linked to an increased propensity for triggered activity. The aim of this study was to determine how InsP3 receptors can translate Ca(2+) release into a depolarization of the plasma membrane and consequently arrhythmic activity. We used embryonic stem cell-derived cardiomyocytes (ESdCs) as a model system since their spontaneous electrical activity depends on InsP3-mediated Ca(2+) release. [InsP3]i was monitored with the FRET-based InsP3-biosensor FIRE-1 (Fluorescent InsP3 Responsive Element) and heterogeneity in sub-cellular [InsP3]i was achieved by targeted expression of FIRE-1 in the nucleus (FIRE-1nuc) or expression of InsP3 5-phosphatase (m43) localized to the plasma membrane. Spontaneous activity of ESdCs was monitored simultaneously as cytosolic Ca(2+) transients (Fluo-4/AM) and action potentials (current clamp). During diastole, the diastolic depolarization was paralleled by an increase of [Ca(2+)]i and spontaneous activity was modulated by [InsP3]i. A 3.7% and 1.7% increase of FIRE-1 FRET ratio and 3.0 and 1.5 fold increase in beating frequency was recorded upon stimulation with endothelin-1 (ET-1, 100 nmol/L) or phenylephrine (PE, 10 µmol/L), respectively. Buffering of InsP3 by FIRE-1nuc had no effect on the basal frequency while attenuation of InsP3 signaling throughout the cell (FIRE-1), or at the plasma membrane (m43) resulted in a 53.7% and 54.0% decrease in beating frequency. In m43 expressing cells the response to ET-1 was completely suppressed. Ca(2+) released from InsP3Rs is more effective than Ca(2+) released from RyRs to enhance INCX. The results support the hypothesis that in ESdCs InsP3Rs form a functional signaling domain with NCX that translates Ca(2+) release efficiently into a depolarization of the membrane potential.
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Affiliation(s)
- Nidhi Kapoor
- Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Joshua T. Maxwell
- Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Gregory A. Mignery
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois, United States of America
| | - David Will
- Center for Cardiovascular Research, Dept. of Medicine, Section of Cardiology, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Lothar A. Blatter
- Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Kathrin Banach
- Center for Cardiovascular Research, Dept. of Medicine, Section of Cardiology, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail:
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29
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Tan R, Li J, Peng X, Zhu L, Cai L, Wang T, Su Y, Irani K, Hu Q. GAPDH is critical for superior efficacy of female bone marrow-derived mesenchymal stem cells on pulmonary hypertension. Cardiovasc Res 2013; 100:19-27. [DOI: 10.1093/cvr/cvt165] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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30
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DeSantiago J, Bare DJ, Ke Y, Sheehan KA, Solaro RJ, Banach K. Functional integrity of the T-tubular system in cardiomyocytes depends on p21-activated kinase 1. J Mol Cell Cardiol 2013; 60:121-8. [PMID: 23612118 PMCID: PMC3679655 DOI: 10.1016/j.yjmcc.2013.04.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 03/06/2013] [Accepted: 04/12/2013] [Indexed: 12/30/2022]
Abstract
p21-activated kinase (Pak1), a serine-threonine protein kinase, regulates cytoskeletal dynamics and cell motility. Recent experiments further demonstrate that loss of Pak1 results in exaggerated hypertrophic growth in response to pathophysiological stimuli. Calcium (Ca) signaling plays an important role in the regulation of transcription factors involved in hypertrophic remodeling. Here we aimed to determine the role of Pak1 in cardiac excitation-contraction coupling (ECC). Ca transients were recorded in isolated, ventricular myocytes (VMs) from WT and Pak1(-/-) mice. Pak1(-/-) Ca transients had a decreased amplitude, prolonged rise time and delayed recovery time. Di-8-ANNEPS staining revealed a decreased T-tubular density in Pak1(-/-) VMs that coincided with decreased cell capacitance and increased dis-synchrony of Ca induced Ca release (CICR) at individual release units. These changes were not observed in atrial myocytes of Pak1(-/-) mice where the T-tubular system is only sparsely developed. Experiments in cultured rabbit VMs supported a role of Pak1 in the maintenance of the T-tubular structure. T-tubular density in rabbit VMs significantly decreased within 24h of culture. This was accompanied by a decrease of the Ca transient amplitude and a prolongation of its rise time. However, overexpression of constitutively active Pak1 in VMs attenuated the structural remodeling as well as changes in ECC. The results provide significant support for a prominent role of Pak1 activity not only in the functional regulation of ECC but for the structural maintenance of the T-tubular system whose remodeling is an integral feature of hypertrophic remodeling.
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Affiliation(s)
- Jaime DeSantiago
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
- Dept. of Medicine, Section of Cardiology, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
| | - Dan J Bare
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
- Dept. of Medicine, Section of Cardiology, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
| | - Yunbo Ke
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
- Dept. of Physiology and Biophysics, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
| | - Katherine A. Sheehan
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
- Dept. of Physiology and Biophysics, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
| | - R. John Solaro
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
- Dept. of Physiology and Biophysics, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
| | - Kathrin Banach
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
- Dept. of Medicine, Section of Cardiology, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
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Drawnel FM, Archer CR, Roderick HL. The role of the paracrine/autocrine mediator endothelin-1 in regulation of cardiac contractility and growth. Br J Pharmacol 2013; 168:296-317. [PMID: 22946456 DOI: 10.1111/j.1476-5381.2012.02195.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2012] [Revised: 08/23/2012] [Accepted: 08/28/2012] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED Endothelin-1 (ET-1) is a critical autocrine and paracrine regulator of cardiac physiology and pathology. Produced locally within the myocardium in response to diverse mechanical and neurohormonal stimuli, ET-1 acutely modulates cardiac contractility. During pathological cardiovascular conditions such as ischaemia, left ventricular hypertrophy and heart failure, myocyte expression and activity of the entire ET-1 system is enhanced, allowing the peptide to both initiate and maintain maladaptive cellular responses. Both the acute and chronic effects of ET-1 are dependent on the activation of intracellular signalling pathways, regulated by the inositol-trisphosphate and diacylglycerol produced upon activation of the ET(A) receptor. Subsequent stimulation of protein kinases C and D, calmodulin-dependent kinase II, calcineurin and MAPKs modifies the systolic calcium transient, myofibril function and the activity of transcription factors that coordinate cellular remodelling. The precise nature of the cellular response to ET-1 is governed by the timing, localization and context of such signals, allowing the peptide to regulate both cardiomyocyte physiology and instigate disease. LINKED ARTICLES This article is part of a themed section on Endothelin. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2013.168.issue-1.
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Affiliation(s)
- Faye M Drawnel
- Babraham Research Campus, Babraham Institute, Cambridge, UK
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32
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Yang HT, Zhang M, Huang J, Liang H, Zhang P, Boheler KR. Cardiomyocytes derived from pluripotent stem cells: Progress and prospects from China. Exp Cell Res 2013; 319:120-5. [DOI: 10.1016/j.yexcr.2012.09.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2012] [Accepted: 09/18/2012] [Indexed: 10/27/2022]
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Wei WJ, Sun HY, Ting KY, Zhang LH, Lee HC, Li GR, Yue J. Inhibition of cardiomyocytes differentiation of mouse embryonic stem cells by CD38/cADPR/Ca2+ signaling pathway. J Biol Chem 2012; 287:35599-35611. [PMID: 22908234 PMCID: PMC3471724 DOI: 10.1074/jbc.m112.392530] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cyclic adenosine diphosphoribose (cADPR) is an endogenous Ca2+ mobilizing messenger that is formed by ADP-ribosyl cyclases from nicotinamide adenine dinucleotide (NAD). The main ADP-ribosyl cyclase in mammals is CD38, a multi-functional enzyme and a type II membrane protein. Here we explored the role of CD38-cADPR-Ca2+ in the cardiomyogenesis of mouse embryonic stem (ES) cells. We found that the mouse ES cells are responsive to cADPR and possess the key components of the cADPR signaling pathway. In vitro cardiomyocyte (CM) differentiation of mouse ES cells was initiated by embryoid body (EB) formation. Interestingly, beating cells appeared earlier and were more abundant in CD38 knockdown EBs than in control EBs. Real-time RT-PCR and Western blot analyses further showed that the expression of several cardiac markers, including GATA4, MEF2C, NKX2.5, and α-MLC, were increased markedly in CD38 knockdown EBs than those in control EBs. Similarly, FACS analysis showed that more cardiac Troponin T-positive CMs existed in CD38 knockdown or 8-Br-cADPR, a cADPR antagonist, treated EBs compared with that in control EBs. On the other hand, overexpression of CD38 in mouse ES cells significantly inhibited CM differentiation. Moreover, CD38 knockdown ES cell-derived CMs possess the functional properties characteristic of normal ES cell-derived CMs. Last, we showed that the CD38-cADPR pathway negatively modulated the FGF4-Erks1/2 cascade during CM differentiation of ES cells, and transiently inhibition of Erk1/2 blocked the enhanced effects of CD38 knockdown on the differentiation of CM from ES cells. Taken together, our data indicate that the CD38-cADPR-Ca2+ signaling pathway antagonizes the CM differentiation of mouse ES cells.
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Affiliation(s)
- Wen-Jie Wei
- Department of Physiology, The University of Hong Kong, Hong Kong, China
| | - Hai-Ying Sun
- Department of Physiology, The University of Hong Kong, Hong Kong, China
| | - Kai Yiu Ting
- Department of Physiology, The University of Hong Kong, Hong Kong, China
| | - Li-He Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Hon-Cheung Lee
- Department of Physiology, The University of Hong Kong, Hong Kong, China
| | - Gui-Rong Li
- Department of Physiology, The University of Hong Kong, Hong Kong, China
| | - Jianbo Yue
- Department of Physiology, The University of Hong Kong, Hong Kong, China.
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Liang X, Mei Y, Huang X, Shen G, Zhu D, Yu Y, Wang J, Lou Y. Junctophilin 2 knockdown interfere with mitochondrium status in ESC-CMs and cardiogenesis of ES cells. J Cell Biochem 2012; 113:2884-94. [DOI: 10.1002/jcb.24164] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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35
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Inositol 1,4,5-trisphosphate receptors and pacemaker rhythms. J Mol Cell Cardiol 2012; 53:375-81. [PMID: 22713798 DOI: 10.1016/j.yjmcc.2012.06.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 06/08/2012] [Indexed: 11/21/2022]
Abstract
Intracellular Ca(2+) plays an important role in the control of the heart rate through the interaction between Ca(2+) release by ryanodine receptors in the sarcoplasmic reticulum (SR) and the extrusion of Ca(2+) by the sodium-calcium exchanger which generates an inward current. A second type of SR Ca(2+) release channel, the inositol 1,4,5-trisphosphate receptor (IP(3)R), can release Ca(2+) from SR stores in many cell types, including cardiac myocytes. However, it is still uncertain whether IP(3)Rs play any functional role in regulating the heart rate. Accumulated evidence shows that IP(3) and IP(3)R are involved in rhythm control in non-cardiac pacemaker tissues and in the embryonic heart. In this review we focus on intracellular Ca(2+) oscillations generated by Ca(2+) release from IP(3)R that initiates membrane depolarization and provides a common mechanism producing spontaneous activity in a range of cells with pacemaker function. Emerging new evidence also suggests that IP(3)/IP(3)Rs play a functional role in normal and diseased hearts and in cardiac rhythm control. Several membrane currents, including a store-operated Ca(2+) current, might be activated by Ca(2+) release from IP(3)Rs. IP(3)/IP(3)R may thus add another dimension to the complex regulation of heart rate.
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Excitation-contraction coupling in ventricular myocytes is enhanced by paracrine signaling from mesenchymal stem cells. J Mol Cell Cardiol 2012; 52:1249-56. [PMID: 22465692 DOI: 10.1016/j.yjmcc.2012.03.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 02/14/2012] [Accepted: 03/12/2012] [Indexed: 12/17/2022]
Abstract
In clinical trials mesenchymal stem cells (MSCs) are transplanted into cardiac ischemic regions to decrease infarct size and improve contractility. However, the mechanism and time course of MSC-mediated cardioprotection are incompletely understood. We tested the hypothesis that paracrine signaling by MSCs promotes changes in cardiac excitation-contraction (EC) coupling that protects myocytes from cell death and enhances contractility. Isolated mouse ventricular myocytes (VMs) were treated with control tyrode, MSC conditioned-tyrode (ConT) or co-cultured with MSCs. The Ca handling properties of VMs were monitored by laser scanning confocal microscopy and whole cell voltage clamp. ConT superfusion of VMs resulted in a time dependent increase of the Ca transient amplitude (ConT(15min): ΔF/F(0)=3.52±0.38, n=14; Ctrl(15min): ΔF/F(0)=2.41±0.35, n=14) and acceleration of the Ca transient decay (τ: ConT: 269±18ms n=14; vs. Ctrl: 315±57ms, n=14). Voltage clamp recordings confirmed a ConT induced increase in I(Ca,L) (ConT: -5.9±0.5 pA/pF n=11; vs. Ctrl: -4.04±0.3 pA/pF, n=12). The change of τ resulted from increased SERCA activity. Changes in the Ca transient amplitude and τ were prevented by the PI3K inhibitors Wortmannin (100nmol/L) and LY294002 (10μmol/L) and the Akt inhibitor V (20μmol/L) indicating regulation through PI3K signal transduction and Akt activation which was confirmed by western blotting. A change in τ was also prevented in eNOS(-/-) myocytes or by inhibition of eNOS suggesting an NO mediated regulation of SERCA activity. Since paracrine signaling further resulted in increased survival of VMs we propose that the Akt induced change in Ca signaling is also a mechanism by which MSCs mediate an anti-apoptotic effect.
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Ju YK, Liu J, Lee BH, Lai D, Woodcock EA, Lei M, Cannell MB, Allen DG. Distribution and Functional Role of Inositol 1,4,5-
tris
phosphate Receptors in Mouse Sinoatrial Node. Circ Res 2011; 109:848-57. [DOI: 10.1161/circresaha.111.243824] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Yue-Kun Ju
- From the School of Medical Sciences and Bosch Institute (Y.K.J., J.L., B.H.L., D.L., D.G.A.), University of Sydney, Sydney, Australia; Baker IDI Heart and Diabetes Institute (E.A.W.), Melbourne, Australia; School of Biomedicine (M.L.), Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; Department of Physiology and Pharmacology (M.B.C.), University of Bristol, Bristol, UK
| | - Jie Liu
- From the School of Medical Sciences and Bosch Institute (Y.K.J., J.L., B.H.L., D.L., D.G.A.), University of Sydney, Sydney, Australia; Baker IDI Heart and Diabetes Institute (E.A.W.), Melbourne, Australia; School of Biomedicine (M.L.), Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; Department of Physiology and Pharmacology (M.B.C.), University of Bristol, Bristol, UK
| | - Bon Hyang Lee
- From the School of Medical Sciences and Bosch Institute (Y.K.J., J.L., B.H.L., D.L., D.G.A.), University of Sydney, Sydney, Australia; Baker IDI Heart and Diabetes Institute (E.A.W.), Melbourne, Australia; School of Biomedicine (M.L.), Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; Department of Physiology and Pharmacology (M.B.C.), University of Bristol, Bristol, UK
| | - Donna Lai
- From the School of Medical Sciences and Bosch Institute (Y.K.J., J.L., B.H.L., D.L., D.G.A.), University of Sydney, Sydney, Australia; Baker IDI Heart and Diabetes Institute (E.A.W.), Melbourne, Australia; School of Biomedicine (M.L.), Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; Department of Physiology and Pharmacology (M.B.C.), University of Bristol, Bristol, UK
| | - Elizabeth A. Woodcock
- From the School of Medical Sciences and Bosch Institute (Y.K.J., J.L., B.H.L., D.L., D.G.A.), University of Sydney, Sydney, Australia; Baker IDI Heart and Diabetes Institute (E.A.W.), Melbourne, Australia; School of Biomedicine (M.L.), Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; Department of Physiology and Pharmacology (M.B.C.), University of Bristol, Bristol, UK
| | - Ming Lei
- From the School of Medical Sciences and Bosch Institute (Y.K.J., J.L., B.H.L., D.L., D.G.A.), University of Sydney, Sydney, Australia; Baker IDI Heart and Diabetes Institute (E.A.W.), Melbourne, Australia; School of Biomedicine (M.L.), Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; Department of Physiology and Pharmacology (M.B.C.), University of Bristol, Bristol, UK
| | - Mark B. Cannell
- From the School of Medical Sciences and Bosch Institute (Y.K.J., J.L., B.H.L., D.L., D.G.A.), University of Sydney, Sydney, Australia; Baker IDI Heart and Diabetes Institute (E.A.W.), Melbourne, Australia; School of Biomedicine (M.L.), Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; Department of Physiology and Pharmacology (M.B.C.), University of Bristol, Bristol, UK
| | - David G. Allen
- From the School of Medical Sciences and Bosch Institute (Y.K.J., J.L., B.H.L., D.L., D.G.A.), University of Sydney, Sydney, Australia; Baker IDI Heart and Diabetes Institute (E.A.W.), Melbourne, Australia; School of Biomedicine (M.L.), Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; Department of Physiology and Pharmacology (M.B.C.), University of Bristol, Bristol, UK
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Sabourin J, Robin E, Raddatz E. A key role of TRPC channels in the regulation of electromechanical activity of the developing heart. Cardiovasc Res 2011; 92:226-36. [PMID: 21672930 DOI: 10.1093/cvr/cvr167] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
AIMS It is well established that dysfunction of voltage-dependent ion channels results in arrhythmias and conduction disturbances in the foetal and adult heart. However, the involvement of voltage-insensitive cationic TRPC (transient receptor potential canonical) channels remains unclear. We assessed the hypothesis that TRPC channels play a crucial role in the spontaneous activity of the developing heart. METHODS AND RESULTS TRPC isoforms were investigated in isolated hearts obtained from 4-day-old chick embryos. Using RT-PCR, western blotting and co-immunoprecipitation, we report for the first time that TRPC1, 3, 4, 5, 6, and 7 isoforms are expressed at the mRNA and protein levels and that they can form a macromolecular complex with the α1C subunit of the L-type voltage-gated calcium channel (Cav1.2) in atria and ventricle. Using ex vivo electrocardiograms, electrograms of isolated atria and ventricle and ventricular mechanograms, we found that inhibition of TRPC channels by SKF-96365 leads to negative chrono-, dromo-, and inotropic effects, prolongs the QT interval, and provokes first- and second-degree atrioventricular blocks. Pyr3, a specific antagonist of TRPC3, affected essentially atrioventricular conduction. On the other hand, specific blockade of the L-type calcium channel with nifedipine rapidly stopped ventricular contractile activity without affecting rhythmic electrical activity. CONCLUSIONS These results give new insights into the key role that TRPC channels, via interaction with the Cav1.2 channel, play in regulation of cardiac pacemaking, conduction, ventricular activity, and contractility during cardiogenesis.
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Affiliation(s)
- Jessica Sabourin
- Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, 7 rue du Bugnon, CH-1005 Lausanne, Switzerland.
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Itzhaki I, Rapoport S, Huber I, Mizrahi I, Zwi-Dantsis L, Arbel G, Schiller J, Gepstein L. Calcium handling in human induced pluripotent stem cell derived cardiomyocytes. PLoS One 2011; 6:e18037. [PMID: 21483779 PMCID: PMC3069979 DOI: 10.1371/journal.pone.0018037] [Citation(s) in RCA: 145] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Accepted: 02/23/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The ability to establish human induced pluripotent stem cells (hiPSCs) by reprogramming of adult fibroblasts and to coax their differentiation into cardiomyocytes opens unique opportunities for cardiovascular regenerative and personalized medicine. In the current study, we investigated the Ca(2+)-handling properties of hiPSCs derived-cardiomyocytes (hiPSC-CMs). METHODOLOGY/PRINCIPAL FINDINGS RT-PCR and immunocytochemistry experiments identified the expression of key Ca(2+)-handling proteins. Detailed laser confocal Ca(2+) imaging demonstrated spontaneous whole-cell [Ca(2+)](i) transients. These transients required Ca(2+) influx via L-type Ca(2+) channels, as demonstrated by their elimination in the absence of extracellular Ca(2+) or by administration of the L-type Ca(2+) channel blocker nifedipine. The presence of a functional ryanodine receptor (RyR)-mediated sarcoplasmic reticulum (SR) Ca(2+) store, contributing to [Ca(2+)](i) transients, was established by application of caffeine (triggering a rapid increase in cytosolic Ca(2+)) and ryanodine (decreasing [Ca(2+)](i)). Similarly, the importance of Ca(2+) reuptake into the SR via the SR Ca(2+) ATPase (SERCA) pump was demonstrated by the inhibiting effect of its blocker (thapsigargin), which led to [Ca(2+)](i) transients elimination. Finally, the presence of an IP3-releasable Ca(2+) pool in hiPSC-CMs and its contribution to whole-cell [Ca(2+)](i) transients was demonstrated by the inhibitory effects induced by the IP3-receptor blocker 2-Aminoethoxydiphenyl borate (2-APB) and the phospholipase C inhibitor U73122. CONCLUSIONS/SIGNIFICANCE Our study establishes the presence of a functional, SERCA-sequestering, RyR-mediated SR Ca(2+) store in hiPSC-CMs. Furthermore, it demonstrates the dependency of whole-cell [Ca(2+)](i) transients in hiPSC-CMs on both sarcolemmal Ca(2+) entry via L-type Ca(2+) channels and intracellular store Ca(2+) release.
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MESH Headings
- Animals
- Biological Transport
- Calcium/metabolism
- Calcium Channels, L-Type/genetics
- Calcium Channels, L-Type/metabolism
- Cell Differentiation
- Cell Line
- Gene Expression Regulation
- Humans
- Induced Pluripotent Stem Cells/cytology
- Inositol 1,4,5-Trisphosphate/metabolism
- Inositol 1,4,5-Trisphosphate Receptors/genetics
- Inositol 1,4,5-Trisphosphate Receptors/metabolism
- Intracellular Space/metabolism
- Mice
- Myocytes, Cardiac/cytology
- Myocytes, Cardiac/enzymology
- Myocytes, Cardiac/metabolism
- Ryanodine Receptor Calcium Release Channel/genetics
- Ryanodine Receptor Calcium Release Channel/metabolism
- Sarcolemma/metabolism
- Sarcoplasmic Reticulum Calcium-Transporting ATPases/genetics
- Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism
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Affiliation(s)
- Ilanit Itzhaki
- Sohnis Family Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Sophia Rapoport
- Department of Biophysics Physiology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Irit Huber
- Sohnis Family Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Itzhak Mizrahi
- Sohnis Family Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Limor Zwi-Dantsis
- Sohnis Family Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Gil Arbel
- Sohnis Family Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Jackie Schiller
- Department of Biophysics Physiology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Lior Gepstein
- Sohnis Family Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
- * E-mail:
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Zahanich I, Sirenko SG, Maltseva LA, Tarasova YS, Spurgeon HA, Boheler KR, Stern MD, Lakatta EG, Maltsev VA. Rhythmic beating of stem cell-derived cardiac cells requires dynamic coupling of electrophysiology and Ca cycling. J Mol Cell Cardiol 2010; 50:66-76. [PMID: 20920509 DOI: 10.1016/j.yjmcc.2010.09.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2010] [Revised: 09/01/2010] [Accepted: 09/27/2010] [Indexed: 12/11/2022]
Abstract
There is an intense interest in differentiating embryonic stem cells to engineer biological pacemakers as an alternative to electronic pacemakers for patients with cardiac pacemaker function deficiency. Embryonic stem cell-derived cardiocytes (ESCs), however, often exhibit dysrhythmic excitations. Using Ca(2+) imaging and patch-clamp techniques, we studied requirements for generation of spontaneous rhythmic action potentials (APs) in late-stage mouse ESCs. Sarcoplasmic reticulum (SR) of ESCs generates spontaneous, rhythmic, wavelet-like Local Ca(2+)Releases (LCRs) (inhibited by ryanodine, tetracaine, or thapsigargin). L-type Ca(2+)current (I(CaL)) induces a global Ca(2+) release (CICR), depleting the Ca(2+) content SR which resets the phases of LCR oscillators. Following a delay, SR then generates a highly synchronized spontaneous Ca(2+)release of multiple LCRs throughout the cell. The LCRs generate an inward Na(+)/Ca(2+)exchanger (NCX) current (absent in Na(+)-free solution) that ignites the next AP. Interfering with SR Ca(2+) cycling (ryanodine, caffeine, thapsigargin, cyclopiazonic acid, BAPTA-AM), NCX (Na(+)-free solution), or I(CaL) (nifedipine) results in dysrhythmic excitations or cessation of automaticity. Inhibition of cAMP/PKA signaling by a specific PKA inhibitor, PKI, decreases SR Ca(2+) loading, substantially reducing both spontaneous LCRs (number, size, and amplitude) and rhythmic AP firing. In contrast, enhancing PKA signaling by cAMP increases the LCRs (number, size, duration) and converts irregularly beating ESCs to rhythmic "pacemaker-like" cells. SR Ca(2+) loading and LCR activity could be also increased with a selective activation of SR Ca(2+) pumping by a phospholamban antibody. We conclude that SR Ca(2+) loading and spontaneous rhythmic LCRs are driven by inherent cAMP/PKA activity. I(CaL) synchronizes multiple LCR oscillators resulting in strong, partially synchronized diastolic Ca(2+) release and NCX current. Rhythmic ESC automaticity can be achieved by boosting "coupling" factors, such as cAMP/PKA signaling, that enhance interactions between SR and sarcolemma.
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Affiliation(s)
- Ihor Zahanich
- Laboratory of Cardiovascular Science, IRP, NIA, NIH, Baltimore, MD 21224-6825, USA
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41
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Lagerqvist EL, Finnin BA, Pouton CW, Haynes JM. Endothelin-1 and angiotensin II modulate rate and contraction amplitude in a subpopulation of mouse embryonic stem cell-derived cardiomyocyte-containing bodies. Stem Cell Res 2010; 6:23-33. [PMID: 20970401 DOI: 10.1016/j.scr.2010.09.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 09/08/2010] [Accepted: 09/10/2010] [Indexed: 11/27/2022] Open
Abstract
Embryonic stem cell-derived cardiomyocytes (ESC-CMs) have applications in understanding cardiac disease pathophysiology, pharmacology, and toxicology. Comprehensive characterization of their basic physiological and pharmacological properties is critical in determining the suitability of ESC-CMs as models of cardiac activity. In this study we use video microscopy and quantitative PCR to investigate the responses of mouse ESC-CMs to adrenoceptor, muscarinic, angiotensin II (Ang II), and endothelin-1 (ET-1) receptor activation. Isoprenaline (10 nM-10 μM) increased beating rate and contraction amplitude in all beating bodies (BBs), whereas carbachol (up to 1 μM) and the I(f) channel blocker ZD-7288 (10 μM) decreased contraction frequency. ET-1 (0.01-100 nM) reduced contraction amplitude in all BBs and increased contraction frequency in 50% of BBs; these effects were blocked by the ET(A) receptor antagonist BQ123 (250 nM). Ang II (0.01 nM-1 μM) increased both contraction amplitude (all BBs) and frequency (in 50% of BBs), effects blocked, respectively, by losartan (100 nM) and PD123,319 (200 nM). These results indicate the presence of functional ET(A) and both AT₁ and AT₂ receptors in murine ESC-CMs, but their expression and or activity appears to be evident only in a limited set of BBs.
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Affiliation(s)
- E L Lagerqvist
- Medicinal Chemistry and Drug Action, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), Melbourne, Australia
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Kim C, Majdi M, Xia P, Wei KA, Talantova M, Spiering S, Nelson B, Mercola M, Chen HSV. Non-cardiomyocytes influence the electrophysiological maturation of human embryonic stem cell-derived cardiomyocytes during differentiation. Stem Cells Dev 2010; 19:783-95. [PMID: 20001453 DOI: 10.1089/scd.2009.0349] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Various types of cardiomyocytes undergo changes in automaticity and electrical properties during fetal heart development. Human embryonic stem cell-derived cardiomyocytes (hESC-CMs), like fetal cardiomyocytes, are electrophysiologically immature and exhibit automaticity. We used hESC-CMs to investigate developmental changes in mechanisms of automaticity and to determine whether electrophysiological maturation is driven by an intrinsic developmental clock and/or is regulated by interactions with non-cardiomyocytes in embryoid bodies (EBs). We isolated pure populations of hESC-CMs from EBs by lentivirus-engineered Puromycin resistance at various stages of differentiation. Using pharmacological agents, calcium (Ca(2+)) imaging, and intracellular recording techniques, we found that intracellular Ca(2+)-cycling mechanisms developed early and contributed to dominant automaticity throughout hESC-CM differentiation. Sarcolemmal ion channels evolved later upon further differentiation within EBs and played an increasing role in controlling automaticity and electrophysiological properties of hESC-CMs. In contrast to the development of intracellular Ca(2+)-handling proteins, ion channel development and electrophysiological maturation of hESC-CMs did not occur when hESC-CMs were isolated from EBs early and maintained in culture without further interaction with non-cardiomyocytes. Adding back non-cardiomyocytes to early-isolated hESC-CMs rescued the arrest of electrophysiological maturation, indicating that non-cardiomyocytes in EBs drive electrophysiological maturation of early hESC-CMs. Non-cardiomyocytes in EBs contain most cell types present in the embryonic heart that are known to influence early cardiac development. Our study is the first to demonstrate that non-cardiomyocytes influence electrophysiological maturation of early hESC-CMs in cultures. Defining the nature of these extrinsic signals will aid in the directed maturation of immature hESC-CMs to mitigate arrhythmogenic risks of cell-based therapies.
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Affiliation(s)
- Changsung Kim
- Center for Neuroscience, Aging and Stem Cell Research, Burnham Institute for Medical Research, La Jolla, California 92037, USA
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Limpitikul W, Christoforou N, Thompson SA, Gearhart JD, Tung L, Lipke EA. Influence of Electromechanical Activity on Cardiac Differentiation of Mouse Embryonic Stem Cells. Cardiovasc Eng Technol 2010; 1:179-193. [PMID: 29057018 PMCID: PMC5647137 DOI: 10.1007/s13239-010-0020-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
During differentiation, mouse embryonic stem cell-derived cardiomyocytes (mESC-CMs) receive electromechanical cues from spontaneous beating. Therefore, promoting electromechanical activity via electrical pacing or suppressing it by drug treatment might affect the cellular functional development. Electrical pacing was applied to confluent monolayers of mESC-CMs during late-stage differentiation (days 16-18). Alternatively, spontaneous contraction was suppressed by (a) blocking ion currents with CsCl (HCN channel), trazodone (T-type Ca2+ channel), or both CsCl and trazodone on days 11-18; or (b) applying blebbistatin (excitation-contraction uncoupler) on days 11-14. Electrophysiological properties and gene expression were examined on day 19 and 18, respectively. Optical mapping revealed no significant difference in conduction velocity (CV)in paced vs. non-pacedmonolayers, nor were there significant changes in gene expression of connexin-43, Na-Ca exchanger (NCX), or myosin heavy chain (MHC). However, CV variability among differentiation batches and CV heterogeneity within individual monolayers were significantly lower in paced mESC-CMs. Alternatively, while the four drug treatments suppressed contraction with varying degrees (up to complete inhibition), there was no significant difference in CV for any of the treatments compared with controls. Trazodone treatment significantly reduced CV variability as compared to controls, whereas CsCl treatment significantly reduced CV heterogeneity. Distinct changes in gene expression of connexin-43, MHC, HCNl, Cav3.1/3.2 were not observed. Electrical pacing, but not suppression of spontaneous contraction, during late-stage differentiation reduces the intrinsic variability of CV among differentiation batches and across individual monolayers, which can be beneficial in the application of ESCs for myocardial tissue repair.
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Affiliation(s)
- Worawan Limpitikul
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | - Susan A. Thompson
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - John D. Gearhart
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Leslie Tung
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Elizabeth A. Lipke
- Department of Chemical Engineering, Auburn University, Auburn, AL 36849, USA
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Caffeine-induced Ca(2+) signaling as an index of cardiac progenitor cells differentiation. Basic Res Cardiol 2010; 105:737-49. [PMID: 20652277 DOI: 10.1007/s00395-010-0111-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 07/07/2010] [Accepted: 07/08/2010] [Indexed: 10/19/2022]
Abstract
Cardiac progenitor cells (CPCs), migrating from heart tissue, in culture aggregate to form cardiospheres (CSs) in which replication and cardiogenic differentiation occur. However, the frequency of functional differentiation in CSs and the role of cell clustering in supporting it remain to be established. The aim of our study is to quantify differentiation of a muscle-type Ca(2+) release mechanism in CS-derived cells, correlate it with cardiac differentiation markers and test its dependency on CS formation. CPCs migrating from murine cardiac explants were studied prior and after CSs formation (Pre-CS and Post-CS). Inducibility of RyR- and IP3-R-mediated Ca(2+) transients in individual cells was tested by exposure to caffeine and ATP, respectively; expression of cardiac and non-cardiac lineage markers was assessed. Caffeine responsiveness was negligible in Pre-CS cells and increased by 7.5 fold in Post-CS cells (3.6 vs. 26.9%; p < 0.05), and was closely correlated with activation of the cardiac TnI gene promoter. ATP-induced responses, frequent in Pre-CS (86%), were slightly increased in Post-CS cells (94%; p < 0.05). Expression of cardiac-specific Ca(2+)-handling proteins (Cav1.2, NCX1, RyR2, SERCA2a) was either limited to the Post-CS stage, or markedly enhanced. CS beating was infrequent, but its pharmacology was compatible with cardiac excitation-contraction coupling. Expression of non-cardiac lineage was low in general, and similar between Pre- and Post-CS cells. Culture conditions inhibiting CSs formation prevented the increase in caffeine responders. In conclusion, clustering in CSs leads to the induction of a muscle-specific functional response in about 30% of CPCs; this is accompanied by development of a cardiac-specific expression pattern.
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Almirza W, Peters P, van Meerwijk W, van Zoelen E, Theuvenet A. Different roles of inositol 1,4,5-trisphosphate receptor subtypes in prostaglandin F2α-induced calcium oscillations and pacemaking activity of NRK fibroblasts. Cell Calcium 2010; 47:544-53. [DOI: 10.1016/j.ceca.2010.05.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Revised: 05/10/2010] [Accepted: 05/11/2010] [Indexed: 11/25/2022]
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Janowski E, Berríos M, Cleemann L, Morad M. Developmental aspects of cardiac Ca(2+) signaling: interplay between RyR- and IP(3)R-gated Ca(2+) stores. Am J Physiol Heart Circ Physiol 2010; 298:H1939-50. [PMID: 20304819 DOI: 10.1152/ajpheart.00607.2009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The dominant mode of intracellular Ca(2+) release in adult mammalian heart is gated by ryanodine receptors (RyRs), but it is less clear whether inositol 1,4,5-trisphosphate (IP(3))-gated Ca(2+) release channels (IP(3)Rs), which are important during embryogenesis, play a significant role during early postnatal development. To address this question, we measured confocal two-dimensional Ca(2+) dependent fluorescence images in acutely isolated neonatal (days 1 to 2) and juvenile (days 8-10) rat cardiomyocytes, either voltage-clamped or permeabilized, where rapid exchange of solution could be used to selectively activate the two types of Ca(2+) release channel. Targeting RyRs with caffeine produced large and rapid Ca(2+) signals throughout the cells. Application of ATP and endothelin-1 to voltage-clamped, or IP(3) to permeabilized, cells produced smaller and slower Ca(2+) signals that were most prominent in subsarcolemmal regions and were suppressed by either the IP(3)R-blocker 2-aminoethoxydiphenylborate or replacement of the biologically active form of IP(3) with its L-stereoisomer. Such IP(3)R-gated Ca(2+) releases were amplified by Ca(2+)-induced Ca(2+) release (CICR) via RyRs since they were also reduced by compounds that block the RyRs (tetracaine) or deplete the Ca(2+) pools they gate (caffeine, ryanodine). Spatial analysis revealed both subsarcolemmal and perinuclear origins for the IP(3)-mediated Ca(2+) release events RyR- and IP(3)R-gated Ca(2+) signals had larger magnitudes in juvenile than in neonatal cardiomyocytes. Ca(2+) signaling was generally quite similar in atrial and ventricular cardiomyocytes but showed divergent development of IP(3)-mediated regulation in juveniles. Our data suggest that an intermediate stage of Ca(2+) signaling may be present in developing cardiomyocytes, where, in addition to RyR-gated Ca(2+) pools, IP(3)-gated Ca(2+) release is sufficiently large in magnitude and duration to trigger or contribute to activation of CICR and cardiac contraction.
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Korhonen T, Rapila R, Ronkainen VP, Koivumäki JT, Tavi P. Local Ca2+ releases enable rapid heart rates in developing cardiomyocytes. J Physiol 2010; 588:1407-17. [PMID: 20211983 DOI: 10.1113/jphysiol.2009.185173] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The ability to generate homogeneous intracellular Ca(2+) oscillations at high frequency is the basis of the rhythmic contractions of mammalian cardiac myocytes. While the specific mechanisms and structures enabling homogeneous high-frequency Ca(2+) signals in adult cardiomyocytes are well characterized, it is not known how these kind of Ca(2+) signals are produced in developing cardiomyocytes. Here we investigated the mechanisms reducing spatial and temporal heterogeneity of cytosolic Ca(2+) signals in mouse embryonic ventricular cardiomyocytes. We show that in developing cardiomyocytes the propagating Ca(2+) signals are amplified in cytosol by local Ca(2+) releases. Local releases are based on regular 3-D sarcoplasmic reticulum (SR) structures containing SR Ca(2+) uptake ATPases (SERCA) and Ca(2+) release channels (ryanodine receptors, RyRs) at regular intervals throughout the cytosol. By evoking [Ca(2+)](i)-induced Ca(2+) sparks, the local release sites promote a 3-fold increase in the cytosolic Ca(2+) propagation speed. We further demonstrate by mathematical modelling that without these local release sites the developing cardiomyocytes lose their ability to generate homogeneous global Ca(2+) signals at a sufficiently high frequency. The mechanism described here is robust and indispensable for normal mammalian cardiomyocyte function from the first heartbeats during the early embryonic phase till terminal differentiation after birth. These results suggest that local cytosolic Ca(2+) releases are indispensable for normal cardiomyocyte development and function of developing heart.
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Affiliation(s)
- Topi Korhonen
- University of Eastern Finland, A.I. Virtanen Institute for Molecular Sciences, Department of Biotechnology and Molecular Medicine, PO Box 1627, FIN-70211 Kuopio, Finland.
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Lakatta EG, Maltsev VA, Vinogradova TM. A coupled SYSTEM of intracellular Ca2+ clocks and surface membrane voltage clocks controls the timekeeping mechanism of the heart's pacemaker. Circ Res 2010; 106:659-73. [PMID: 20203315 PMCID: PMC2837285 DOI: 10.1161/circresaha.109.206078] [Citation(s) in RCA: 453] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ion channels on the surface membrane of sinoatrial nodal pacemaker cells (SANCs) are the proximal cause of an action potential. Each individual channel type has been thoroughly characterized under voltage clamp, and the ensemble of the ion channel currents reconstructed in silico generates rhythmic action potentials. Thus, this ensemble can be envisioned as a surface "membrane clock" (M clock). Localized subsarcolemmal Ca(2+) releases are generated by the sarcoplasmic reticulum via ryanodine receptors during late diastolic depolarization and are referred to as an intracellular "Ca(2+) clock," because their spontaneous occurrence is periodic during voltage clamp or in detergent-permeabilized SANCs, and in silico as well. In spontaneously firing SANCs, the M and Ca(2+) clocks do not operate in isolation but work together via numerous interactions modulated by membrane voltage, subsarcolemmal Ca(2+), and protein kinase A and CaMKII-dependent protein phosphorylation. Through these interactions, the 2 subsystem clocks become mutually entrained to form a robust, stable, coupled-clock system that drives normal cardiac pacemaker cell automaticity. G protein-coupled receptors signaling creates pacemaker flexibility, ie, effects changes in the rhythmic action potential firing rate, by impacting on these very same factors that regulate robust basal coupled-clock system function. This review examines evidence that forms the basis of this coupled-clock system concept in cardiac SANCs.
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Affiliation(s)
- Edward G Lakatta
- Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging/NIH, 5600 Nathan Shock Dr., Baltimore, MD 21224-6825, USA.
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Sedan O, Dolnikov K, Zeevi-Levin N, Fleishmann N, Spiegel I, Berdichevski S, Amit M, Itskovitz-Eldor J, Binah O. Human embryonic stem cell-derived cardiomyocytes can mobilize 1,4,5-inositol trisphosphate-operated [Ca2+]i stores. Ann N Y Acad Sci 2010; 1188:68-77. [DOI: 10.1111/j.1749-6632.2009.05085.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Lieu DK, Liu J, Siu CW, McNerney GP, Tse HF, Abu-Khalil A, Huser T, Li RA. Absence of transverse tubules contributes to non-uniform Ca(2+) wavefronts in mouse and human embryonic stem cell-derived cardiomyocytes. Stem Cells Dev 2010; 18:1493-500. [PMID: 19290776 DOI: 10.1089/scd.2009.0052] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Mouse (m) and human embryonic stem cell-derived cardiomyocytes (hESC-CMs) are known to exhibit immature Ca(2+) dynamics such as small whole-cell peak amplitude and slower kinetics relative to those of adult. In this study, we examined the maturity and efficiency of Ca(2+)-induced Ca(2+) release in m and hESC-CMs, the presence of transverse (t) tubules and its effects on the regional Ca(2+) dynamics. In m and hESC-CMs, fluorescent staining and atomic force microscopy (AFM) were used to detect the presence of t-tubules, caveolin-3, amphiphysin-2 and colocalization of dihydropyridine receptors (DHPRs) and ryanodine receptors (RyRs). To avoid ambiguities, regional electrically-stimulated Ca(2+) dynamics of single ESC-CMs, rather than spontaneously beating clusters, were measured using confocal microscopy. m and hESC-CMs showed absence of dyads, with neither t-tubules nor colocalization of DHPRs and RyRs. Caveolin-3 and amphiphysin-2, crucial for the biogenesis of t-tubules with robust expression in adult CMs, were also absent. Single m and hESC-CMs displayed non-uniform Ca(2+) dynamics across the cell that is typical of CMs deficient of t-tubules. Local Ca(2+) transients exhibited greater peak amplitude at the peripheral than at the central region for m (3.50 +/- 0.42 vs. 3.05 +/- 0.38) and hESC-CMs (2.96 +/- 0.25 vs. 2.72 +/- 0.25). Kinetically, both the rates of rise to peak amplitude and transient decay were faster for the peripheral relative to the central region. Immature m and hESC-CMs display unsynchronized Ca(2+) transients due to the absence of t-tubules and gene products crucial for their biogenesis. Our results provide insights for driving the maturation of ESC-CMs.
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Affiliation(s)
- Deborah K Lieu
- Human Embryonic Cell Consortium, Stem Cell Program, University of California, Davis, Sacramento, CA 95817, USA.
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