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Cardiac calcium signaling in health and disease: role of SR Ca2+ release and ryanodine receptor release channels (RyRs)

English title Cardiac calcium signaling in health and disease: role of SR Ca2+ release and ryanodine receptor release channels (RyRs)
Applicant Niggli Ernst
Number 156375
Funding scheme Project funding (Div. I-III)
Research institution Institut für Physiologie Medizinische Fakultät Universität Bern
Institution of higher education University of Berne - BE
Main discipline Cardiovascular Research
Start/End 01.10.2014 - 31.05.2018
Approved amount 625'000.00
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Keywords (6)

cardiomyocyte; ryanodine receptor; sarcoplasmic reticulum; calcium signaling; cardiac muscle; excitation-contraction coupling

Lay Summary (German)

Lead
Bei vielen Herzkrankheiten führt eine Beeinträchtigung der zellulären Kalziumsignale zu einer Schwächung des Herzmuskels. In diesem Projekt wird die Funktion der Proteine, welche diese Signale kontrollieren, untersucht. Das Verständnis von pathologischen Funktionsänderungen dieser Proteine wird die Entwicklung neuer Therapiekonzepte ermöglichen.
Lay summary

Hintergrund:

Seit geraumer Zeit ist bekannt, dass die Funktion des Kalziumsignalsystems der Herzmuskelzellen bei vielen Krankheiten gestört ist. Dieser Umstand ist für die inadäquate Herzmuskelkraft in solchen Situationen verantwortlich, aber auch für Rhythmusstörungen des Herzens. Jede Herzmuskelzelle besitzt einen eingebauten “Verstärker” für Kalziumsignale, bestehend aus einem Kalziumspeicher (das sarkoplasmatische Retikulum), Kanalproteinen zur Kalziumfreisetzung, und sogenannte Kalziumpumpen zum Wiederauffüllen des Speichers. Krankheitsbedingte oder vererbbare Veränderungen der Funktion der Kanalproteine, auch Ryanodinrezeptoren genannt, stehen im Zentrum dieses Projekts, da diese zu Herzmuskelschwäche und lebensbedrohlichen Herzrhythmusstörungen führen können, ja sogar zum plötzlichen Herztod.

Ziel:

In diesem Projekt werden wir Funktionsänderungen dieses Kanals, wie sie im Rahmen verschiedener physiologischer regulatorischer Vorgänge oder bei Erkrankungen auftreten können, mit biophysikalischen und bildgebenden Methoden an isolierten Herzmuskelzellen untersuchen. Wir werden die Hypothese testen, dass verschiedene Störungen letzten Endes ganz ähnliche und zum Teil additive Funktionsänderungen dieser Kanäle bewirken. Zu den Störungen gehören zum Beispiel Funktionsänderungen infolge von Stress, aber auch vererbbare Mutationen in diesem Kanal.

Bedeutung:

Erkrankungen des Herz-Kreislaufsystems sind nach wie vor die wichtigste Todesursache in allen Industrienationen. Die Herzmuskelschwächen sind leider immer noch nicht adäquat behandelbar, aber deren Häufigkeit nimmt in der alternden Bevölkerung stetig zu und wird endemische Proportionen annehmen. Ein verbessertes Verständnis der zugrunde liegenden Pathomechanismen wird für die zukünftige Entwicklung neuer Behandlungsmethoden von zentraler Bedeutung sein.

 

Direct link to Lay Summary Last update: 29.09.2014

Responsible applicant and co-applicants

Employees

Publications

Publication
Simultaneous recording of subcellular Ca2+ signals from the cytosol and sarco/endoplasmatic reticulum: compartmentalized dye loading, imaging and analysis.
Niggli Ernst, Fernandez-Tenorio Miguel (2019), Simultaneous recording of subcellular Ca2+ signals from the cytosol and sarco/endoplasmatic reticulum: compartmentalized dye loading, imaging and analysis., in Methods in Molecular Biology, 1929(5), 53-71.
Reassessment of the Transport Mechanism of the Human Zinc Transporter SLC39A2
Franz Marie C., Pujol-Giménez Jonai, Montalbetti Nicolas, Fernandez-Tenorio Miguel, DeGrado Timothy R., Niggli Ernst, Romero Michael F., Hediger Matthias A. (2018), Reassessment of the Transport Mechanism of the Human Zinc Transporter SLC39A2, in Biochemistry, 57(26), 3976-3986.
Stabilization of Ca 2+ signaling in cardiac muscle by stimulation of SERCA
Fernandez-Tenorio Miguel, Niggli Ernst (2018), Stabilization of Ca 2+ signaling in cardiac muscle by stimulation of SERCA, in Journal of Molecular and Cellular Cardiology, 87-95.
Bacopa monnieri extract increases rat coronary flow and protects against myocardial ischemia/reperfusion injury.
Srimachai Sirintorn, Devaux Sylvie, Demougeot Celine, Kumphune Sarawut, Ullrich Nina D, Niggli Ernst, Ingkaninan Kornkanok, Kamkaew Natakorn, Scholfield C Norman, Tapechum Sompol, Chootip Krongkarn (2017), Bacopa monnieri extract increases rat coronary flow and protects against myocardial ischemia/reperfusion injury., in BMC complementary and alternative medicine, (1), 117-117.
Calcium Uncaging with Visible Light.
Agarwal Hitesh K, Janicek Radoslav, Chi San-Hui, Perry Joseph W, Niggli Ernst, Ellis-Davies Graham C R (2016), Calcium Uncaging with Visible Light., in Journal of the American Chemical Society, (11), 3687-3693.
Cardiomyocyte Lineage Specification in Adult Human Cardiac Precursor Cells Via Modulation of Enhancer-Associated Long Noncoding RNA Expression
Plaisance Isabelle, Perruchoud St{é}}phanie, Fernandez-Tenorio Miguel, Gonzales Christine, Ounzain Samir, Ruchat Patrick, Nemir Mohamed, Niggli Ernst, Pedrazzini Thierry (2016), Cardiomyocyte Lineage Specification in Adult Human Cardiac Precursor Cells Via Modulation of Enhancer-Associated Long Noncoding RNA Expression, in {JACC}: Basic to Translational Science, (6), 472-493.
One and Two-Photon Calcium Uncaging with Visible Light in Cardiac Myocytes
Janicek Radoslav, Agarwal Hitesh K., Ellis-Davies Graham C.R., Niggli Ernst (2016), One and Two-Photon Calcium Uncaging with Visible Light in Cardiac Myocytes, in Biophysical Journal, (3), 432-432.
Protein Phosphatase-1 Increases Calcium Spark Frequency in Murine Cardiomyocytes via Modulation of RyR2 Phosphorylation
Potenza Duilio Michele, Fernandez-Tenorio Miguel, Niggli Ernst (2016), Protein Phosphatase-1 Increases Calcium Spark Frequency in Murine Cardiomyocytes via Modulation of RyR2 Phosphorylation, in Biophysical Journal, (3), 269-270.
Real-time intra-store confocal Ca2+ imaging in isolated mouse cardiomyocytes
Fernandez-Tenorio Miguel, Niggli Ernst (2016), Real-time intra-store confocal Ca2+ imaging in isolated mouse cardiomyocytes, in Cell Calcium, (5), 331-340.
Dystrophic cardiomyopathy: role of TRPV2 channels in stretch-induced cell damage
Lorin C., Vogeli I., Niggli E. (2015), Dystrophic cardiomyopathy: role of TRPV2 channels in stretch-induced cell damage, in Cardiovascular Research, (1), 153-162.
IP3 and Ca2+ signals in the heart: boost them or bust them?
Niggli Ernst (2015), IP3 and Ca2+ signals in the heart: boost them or bust them?, in JOURNAL OF PHYSIOLOGY-LONDON, (6), 1385-1386.
Opposite Changes of Ca2+ Wave Threshold and Fractional SR Ca2+ Release during SERCA Stimulation in Cardiomyocytes
Fernandez-Tenorio Miguel, Niggli Ernst (2015), Opposite Changes of Ca2+ Wave Threshold and Fractional SR Ca2+ Release during SERCA Stimulation in Cardiomyocytes, in Biophysical Journal, (2), 263-263.
Maximal acceleration of calcium release refractoriness by β-adrenergic stimulation requires dual activation of protein kinase A and CaMKII in mouse ventricular myocytes
Poláková Eva, Illaste Ardo, Niggli Ernst, Sobie Eric A. (2014), Maximal acceleration of calcium release refractoriness by β-adrenergic stimulation requires dual activation of protein kinase A and CaMKII in mouse ventricular myocytes, in J Physiol, (6), 1495-1507.
Oxidative Stress and Ca2+ Release Events in Mouse Cardiomyocytes
Shirokova Natalia, Kang Chifei, Fernandez-Tenorio Miguel, Wang Wei, Wang Qiongling, Wehrens Xander H. T., Niggli Ernst (2014), Oxidative Stress and Ca2+ Release Events in Mouse Cardiomyocytes, in BIOPHYSICAL JOURNAL, (12), 2815-2827.

Collaboration

Group / person Country
Types of collaboration
Ana Gomez, INSERM, Paris France (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
- Exchange of personnel
Thierry Pedrazzini, CHUV, Uni Lausanne Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
- Exchange of personnel
Natalia Shirokova, Rutgers University, NJ United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
- Exchange of personnel
Hector Valdivia, Physiology, U. Michigan United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Matthias Hediger, IBMM, Bern Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
- Exchange of personnel
Krongkarn Chootip, Naresuan University Thailand (Asia)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
- Exchange of personnel
Graham Ellis-Davies United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Eric Sobie, Mount Sinai Hospital, NY United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
- Exchange of personnel

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
LS2 Cardiovascular Biology Intersection meeting 2018 Talk given at a conference The RyR2R420Q mutation triggers catecholaminergic polymorphic ventricular tachycardia in mouse cardiomyocytes via SR calcium loading 15.03.2018 Fribourg, Switzerland Potenza Duilio Michele; Janicek Radoslav; Niggli Ernst;
Annual Meeting of the Biophysical Society 2018 Poster The RyR2R420Q Mutation Triggers Catecholaminergic Polymorphic Ventricular Tachycardia in Mouse Cardiomyocytes via SR Calcium Loading 17.02.2018 San Francisco, United States of America Niggli Ernst; Janicek Radoslav; Potenza Duilio Michele;
Gordon Research Conference Muscle: Excitation-Contraction Coupling 2017 Talk given at a conference Ablation of the RyR2-Ser2030 phosphorylation site limits changes in RyR2 sensitivity during β-adrenergic stimulation 04.06.2017 Les Diablerets, Switzerland Potenza Duilio Michele; Niggli Ernst; Janicek Radoslav;
Annual Meeting of the Biophysical Society 2017 Poster Ablation of the RyR2-Ser2030 phosphorylation site limits changes in RyR2 sensitivity during ß-adrenergic stimulation. 11.02.2017 New Orleans, United States of America Niggli Ernst; Janicek Radoslav; Potenza Duilio Michele;
Cardiovascular and Metabolic Research Meeting 2017 Talk given at a conference Ablation of the RyR2-Ser2030 phosphorylation site limits changes in RyR2 sensitivity during β–adrenergic stimulation. 19.01.2017 Fribourg, Switzerland Potenza Duilio Michele; Janicek Radoslav; Niggli Ernst;
Gordon Research Conference 2016 Poster Protein Phosphatase-1 Increases Calcium Spark Frequency in Murine Cardiomyocytes via Modulation of RYR2 Phosphorylation 05.06.2016 New London NH, United States of America Janicek Radoslav; Potenza Duilio Michele; Niggli Ernst;
Annual Meeting of the Biophysical Society 2016 Poster Protein Phosphatase-1 Increases Calcium Spark Frequency in Murine Cardiomyocytes via Modulation of RYR2 Phosphorylation 27.02.2016 Los Angeles CA, United States of America Niggli Ernst; Janicek Radoslav; Potenza Duilio Michele;
Cardiovascular and Metabolic Research Meeting 2016 Poster Protein Phosphatase-1 Increases Calcium Spark Frequency in Murine Cardiomyocytes via Modulation of RYR2 Phosphorylation 14.01.2016 Fribourg, Switzerland Niggli Ernst; Potenza Duilio Michele; Janicek Radoslav;
33RD ANNUAL MEETING OF THE EUROPEAN SECTION OF THE ISHR 2015 Talk given at a conference Post-Translational Modifications of Ryanodine Receptors 01.07.2015 Bordeaux, France Niggli Ernst;
Gordon Research Conference: Muscle: Excitation-contraction coupling 2015 Talk given at a conference Dystrophic Cardiomyopathy - Role of TRPV2 Channels in Stretch-Induced Cell Damage 31.05.2015 Sunday River ME, United States of America Niggli Ernst;
Annual Meeting of the Biophysical Society 2015 Poster SERCA stimulation increases intra-SR Ca2+ threshold for Ca2+ waves in cardiomyocyte 07.02.2015 Baltimore MD, United States of America Niggli Ernst;


Awards

Title Year
Poster prize (3rd.) of the LS2 Cardiovascular Intersection meeting 2018
Physiology Section of the LS2: Young Investigator Award 2017

Associated projects

Number Title Start Funding scheme
179325 Cardiac calcium signaling in health and disease: role of SR Ca2+ release and ryanodine receptor release channels (RyRs) 01.06.2018 Project funding (Div. I-III)
132689 Calcium signaling in the heart: Role of SR Ca2+ release channels (RyRs) in health and disease 01.10.2010 Project funding (Div. I-III)

Abstract

1.1. Background and rationale:In cardiac muscle, contraction is activated by transient elevations of the intracellular Ca2+ concentration. The mechanisms governing these Ca2+ signals are referred to as excitation-contraction (EC) coupling. A small amount of Ca2+ entering the myocytes via voltage-dependent Ca2+ channels is amplified several-fold by the mechanism of Ca2+-induced Ca2+ release (CICR) from the sarcoplasmic reticulum (SR) via Ca2+ release channels (called ryanodine receptors or RyRs). The RyRs are thus the gatekeepers of EC-coupling. They form huge tetrameric macromolecular complexes. Opening and closing of the RyRs is modulated by a variety of post-translational modifications, and by cellular constituents and ions, all of which converge in their action on the RyRs and eventually impinge on this protein. The overarching goal of this project is to define the function of the RyRs in health and disease, and to characterize how these channels shape Ca2+ signaling, EC-coupling and arrhythmogenicity. We will concentrate our experimental efforts on 3 parameters associated with Ca2+ signaling and RyR function, carefully selected because of their importance in physiological regulation of cardiac muscle activity, but also because of their pathophysiological relevance. The following mechanisms will be defined: 1) Regulation of RyR activity by ß-adrenergic receptor (ß-AR) stimulation and RyR phosphorylation. 2) Changes of RyR function resulting from arrhythmogenic RyR mutations found in man. 3) The mechanism(s) which actually destabilizes such mutated RyRs during ß-AR stimulation to precipitate life-threatening arrhythmias.1.2. Working hypothesis:We hypothesize that in cardiac muscle each of the three mechanisms mentioned above can independently affect the Ca2+ sensitivity of the RyRs and ultimately modify the gating of these channels. This also implies the testable hypothesis that the mechanisms contribute synergistically (or additively) to the functional state of the RyR macromolecular complex. 1.3. Specific aims: In this project we will follow three specific aims examining the three mechanisms listed above, logically linked by their common mechanism to modulate RyR function. In aim 1 we will assess how RyR function is modified by ß-AR stimulation, focussing on RyR phosphorylation at an underexplored specific phosphorylation site. This will involve studies on the RyR activity at rest (i.e. between heartbeats), during triggered Ca2+ release events (i.e. during systole) and during arrhythmic events (i.e. Ca2+ waves). In aim 2 we will elucidate how destabilizing and arrhythmogenic RyR mutations found in human patients interfere with EC-coupling and Ca2+ signaling. In aim 3 we will examine by which mechanism(s) ß-AR stimulation affects the Ca2+ sensitivity of the mutated RyRs, leading to arrhythmogenic Ca2+ waves, with particular focus on changes of SR Ca2+ loading, changes of RyR phosphorylation and oxidative stress, all occurring simultaneously during ß-AR stimulation.1.4. Experimental design:The strategy to examine the functional role of one specific RyR phosphorylation site (out of 3) is based on two animal models. One transgenic mouse carries a RyR that cannot be phosphorylated at a specific serine residue (S2030), the other model is lacking the two other phosphorylation sites (S2808, S2814) but has an intact S2030. Functional consequences of two arrhythmogenic RyR mutations identified in humans will be examined in transgenic mice harboring identical mutations, and recapitulating the human disease. 1.5. Specific methods:Confocal imaging of Ca2+ signals (transients, sparks, waves) in isolated cardiomyocytes will be combined with cellular electrophysiology techniques (patch-clamp) and photolysis of caged compounds, a combination of techniques that was pioneered by our laboratory. Intact, but also permeabilized myocytes will be used for the proposed studies, the latter mainly for recordings of Ca2+ signals from inside the SR. To derive information about the RyR function under specific conditions, we will analyze Ca2+ spark parameters (e.g. frequency, amplitude, restitution) and intra-SR Ca2+ wave thresholds. We will also analyze the reliability of the signal transduction from the L-type Ca2+ channels to the RyRs by assaying macroscopic and microscopic EC-coupling gain functions, which are indicators of reliable RyR gating. This will be complemented by blotting techniques, to quantify protein expression, phosphorylation and oxidation.1.6. Expected value of the proposed project:With the proposed experiments we expect to obtain new information about fundamental cellular and molecular mechanisms that enable the heart to regulate the produced force and how this regulation may be impaired in cardiac diseases. The RyRs are now considered a promising drug target and a new class of pharmacological compounds stabilizing the RyRs (so called “Rycals”) are under development. Thus, besides our genuine interest to comprehend the functioning of cardiac Ca2+ release and EC-coupling, a detailed mechanistic and pathomechanistic understanding of the RyRs is of crucial importance. With the approach presented here we hope to gain key information about some of these important mechanisms and how they interact synergistically or deleteriously by their ability to change RyR function in favorable or harmful ways, particularly in patients carrying arrhythmogenic RyR mutations.
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