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Edwards AG, Grandi E, Hake JE, Patel S, Li P, Miyamoto S, Omens JH, Heller Brown J, Bers DM, McCulloch AD. Nonequilibrium reactivation of Na+ current drives early afterdepolarizations in mouse ventricle. Circ Arrhythm Electrophysiol 2014; 7:1205-13. [PMID: 25236710 DOI: 10.1161/circep.113.001666] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Early afterdepolarizations (EADs) are triggers of cardiac arrhythmia driven by L-type Ca(2+) current (ICaL) reactivation or sarcoplasmic reticulum Ca(2+) release and Na(+)/Ca(2+) exchange. In large mammals the positive action potential plateau promotes ICaL reactivation, and the current paradigm holds that cardiac EAD dynamics are dominated by interaction between ICaL and the repolarizing K(+) currents. However, EADs are also frequent in the rapidly repolarizing mouse action potential, which should not readily permit ICaL reactivation. This suggests that murine EADs exhibit unique dynamics, which are key for interpreting arrhythmia mechanisms in this ubiquitous model organism. We investigated these dynamics in myocytes from arrhythmia-susceptible calcium calmodulin-dependent protein kinase II delta C (CaMKIIδC)-overexpressing mice (Tg), and via computational simulations. METHODS AND RESULTS In Tg myocytes, β-adrenergic challenge slowed late repolarization, potentiated sarcoplasmic reticulum Ca(2+) release, and initiated EADs below the ICaL activation range (-47 ± 0.7 mV). These EADs were abolished by caffeine and tetrodotoxin (but not ranolazine), suggesting that sarcoplasmic reticulum Ca(2+) release and Na(+) current (INa), but not late INa, are required for EAD initiation. Simulations suggest that potentiated sarcoplasmic reticulum Ca(2+) release and Na(+)/Ca(2+) exchange shape late action potential repolarization to favor nonequilibrium reactivation of INa and thereby drive the EAD upstroke. Action potential clamp experiments suggest that lidocaine eliminates virtually all inward current elicited by EADs, and that this effect occurs at concentrations (40-60 μmol/L) for which lidocaine remains specific for inactivated Na(+) channels. This strongly suggests that previously inactive channels are recruited during the EAD upstroke, and that nonequilibrium INa dynamics underlie murine EADs. CONCLUSIONS Nonequilibrium reactivation of INa drives murine EADs.
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Affiliation(s)
- Andrew G Edwards
- From the Department of Bioengineering (A.G.E., S.P., J.H.O., A.D.M.), Department of Pharmacology (S.M., J.H.B.), University of California, San Diego, La Jolla; Department of Pharmacology, University of California, Davis (E.G., D.M.B.); and Simula Research Laboratory, Center for Biomedical Computing, Lysaker, Oslo, Norway (J.E.H., P.L.).
| | - Eleonora Grandi
- From the Department of Bioengineering (A.G.E., S.P., J.H.O., A.D.M.), Department of Pharmacology (S.M., J.H.B.), University of California, San Diego, La Jolla; Department of Pharmacology, University of California, Davis (E.G., D.M.B.); and Simula Research Laboratory, Center for Biomedical Computing, Lysaker, Oslo, Norway (J.E.H., P.L.)
| | - Johan E Hake
- From the Department of Bioengineering (A.G.E., S.P., J.H.O., A.D.M.), Department of Pharmacology (S.M., J.H.B.), University of California, San Diego, La Jolla; Department of Pharmacology, University of California, Davis (E.G., D.M.B.); and Simula Research Laboratory, Center for Biomedical Computing, Lysaker, Oslo, Norway (J.E.H., P.L.)
| | - Sonia Patel
- From the Department of Bioengineering (A.G.E., S.P., J.H.O., A.D.M.), Department of Pharmacology (S.M., J.H.B.), University of California, San Diego, La Jolla; Department of Pharmacology, University of California, Davis (E.G., D.M.B.); and Simula Research Laboratory, Center for Biomedical Computing, Lysaker, Oslo, Norway (J.E.H., P.L.)
| | - Pan Li
- From the Department of Bioengineering (A.G.E., S.P., J.H.O., A.D.M.), Department of Pharmacology (S.M., J.H.B.), University of California, San Diego, La Jolla; Department of Pharmacology, University of California, Davis (E.G., D.M.B.); and Simula Research Laboratory, Center for Biomedical Computing, Lysaker, Oslo, Norway (J.E.H., P.L.)
| | - Shigeki Miyamoto
- From the Department of Bioengineering (A.G.E., S.P., J.H.O., A.D.M.), Department of Pharmacology (S.M., J.H.B.), University of California, San Diego, La Jolla; Department of Pharmacology, University of California, Davis (E.G., D.M.B.); and Simula Research Laboratory, Center for Biomedical Computing, Lysaker, Oslo, Norway (J.E.H., P.L.)
| | - Jeffrey H Omens
- From the Department of Bioengineering (A.G.E., S.P., J.H.O., A.D.M.), Department of Pharmacology (S.M., J.H.B.), University of California, San Diego, La Jolla; Department of Pharmacology, University of California, Davis (E.G., D.M.B.); and Simula Research Laboratory, Center for Biomedical Computing, Lysaker, Oslo, Norway (J.E.H., P.L.)
| | - Joan Heller Brown
- From the Department of Bioengineering (A.G.E., S.P., J.H.O., A.D.M.), Department of Pharmacology (S.M., J.H.B.), University of California, San Diego, La Jolla; Department of Pharmacology, University of California, Davis (E.G., D.M.B.); and Simula Research Laboratory, Center for Biomedical Computing, Lysaker, Oslo, Norway (J.E.H., P.L.)
| | - Donald M Bers
- From the Department of Bioengineering (A.G.E., S.P., J.H.O., A.D.M.), Department of Pharmacology (S.M., J.H.B.), University of California, San Diego, La Jolla; Department of Pharmacology, University of California, Davis (E.G., D.M.B.); and Simula Research Laboratory, Center for Biomedical Computing, Lysaker, Oslo, Norway (J.E.H., P.L.)
| | - Andrew D McCulloch
- From the Department of Bioengineering (A.G.E., S.P., J.H.O., A.D.M.), Department of Pharmacology (S.M., J.H.B.), University of California, San Diego, La Jolla; Department of Pharmacology, University of California, Davis (E.G., D.M.B.); and Simula Research Laboratory, Center for Biomedical Computing, Lysaker, Oslo, Norway (J.E.H., P.L.)
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202
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Dobrev D, Wehrens XHT. Role of RyR2 phosphorylation in heart failure and arrhythmias: Controversies around ryanodine receptor phosphorylation in cardiac disease. Circ Res 2014; 114:1311-9; discussion 1319. [PMID: 24723656 DOI: 10.1161/circresaha.114.300568] [Citation(s) in RCA: 131] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cardiac ryanodine receptor type 2 plays a key role in excitation-contraction coupling. The ryanodine receptor type 2 channel protein is modulated by various post-translational modifications, including phosphorylation by protein kinase A and Ca(2+)/calmodulin protein kinase II. Despite extensive research in this area, the functional effects of ryanodine receptor type 2 phosphorylation remain disputed. In particular, the potential involvement of increased ryanodine receptor type 2 phosphorylation in the pathogenesis of heart failure and arrhythmias remains a controversial area, which is discussed in this review article.
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Affiliation(s)
- Dobromir Dobrev
- From the Institute of Pharmacology, Faculty of Medicine, University Duisburg-Essen, Essen, Germany (D.D.); and Cardiovascular Research Institute, Departments of Molecular Physiology and Biophysics, and Medicine-Cardiology, Baylor College of Medicine, Houston, TX (X.H.T.W.)
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203
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Fischer TH, Eiringhaus J, Dybkova N, Förster A, Herting J, Kleinwächter A, Ljubojevic S, Schmitto JD, Streckfuß‐Bömeke K, Renner A, Gummert J, Hasenfuss G, Maier LS, Sossalla S. Ca
2+
/calmodulin‐dependent protein kinase
II
equally induces sarcoplasmic reticulum Ca
2+
leak in human ischaemic and dilated cardiomyopathy. Eur J Heart Fail 2014; 16:1292-300. [DOI: 10.1002/ejhf.163] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 07/28/2014] [Accepted: 08/01/2014] [Indexed: 11/06/2022] Open
Affiliation(s)
- Thomas H. Fischer
- Abteilung Kardiologie und Pneumologie/Herzzentrum Georg‐August‐Universität Göttingen Germany
| | - Jörg Eiringhaus
- Abteilung Kardiologie und Pneumologie/Herzzentrum Georg‐August‐Universität Göttingen Germany
| | - Nataliya Dybkova
- Abteilung Kardiologie und Pneumologie/Herzzentrum Georg‐August‐Universität Göttingen Germany
| | - Anna Förster
- Abteilung Kardiologie und Pneumologie/Herzzentrum Georg‐August‐Universität Göttingen Germany
| | - Jonas Herting
- Abteilung Kardiologie und Pneumologie/Herzzentrum Georg‐August‐Universität Göttingen Germany
| | - Astrid Kleinwächter
- Abteilung Kardiologie und Pneumologie/Herzzentrum Georg‐August‐Universität Göttingen Germany
| | - Senka Ljubojevic
- Abteilung Kardiologie Medizinische Universitätsklinik Graz Austria
| | - Jan D. Schmitto
- Abteilung Herz‐, Thorax‐, Gefäß‐ und Transplantationschirurgie Medizinische Hochschule Hannover Germany
| | - Katrin Streckfuß‐Bömeke
- Abteilung Kardiologie und Pneumologie/Herzzentrum Georg‐August‐Universität Göttingen Germany
| | - André Renner
- Abteilung Thorax‐, Herz‐, Gefäßchirurgie Herz‐ und Diabeteszentrum Nordrheinwestfalen Bad Oeynhausen Germany
| | - Jan Gummert
- Abteilung Thorax‐, Herz‐, Gefäßchirurgie Herz‐ und Diabeteszentrum Nordrheinwestfalen Bad Oeynhausen Germany
| | - Gerd Hasenfuss
- Abteilung Kardiologie und Pneumologie/Herzzentrum Georg‐August‐Universität Göttingen Germany
- German Center for Cardiovascular Research (DZHK) Partner Site Goettingen Germany
| | - Lars S. Maier
- Klinik und Poliklinik für Innere Medizin II Uiversitätsklinikum Regensburg Germany
| | - Samuel Sossalla
- Abteilung Kardiologie und Pneumologie/Herzzentrum Georg‐August‐Universität Göttingen Germany
- German Center for Cardiovascular Research (DZHK) Partner Site Goettingen Germany
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204
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Kreusser MM, Lehmann LH, Keranov S, Hoting MO, Oehl U, Kohlhaas M, Reil JC, Neumann K, Schneider MD, Hill JA, Dobrev D, Maack C, Maier LS, Gröne HJ, Katus HA, Olson EN, Backs J. Cardiac CaM Kinase II genes δ and γ contribute to adverse remodeling but redundantly inhibit calcineurin-induced myocardial hypertrophy. Circulation 2014; 130:1262-73. [PMID: 25124496 DOI: 10.1161/circulationaha.114.006185] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Ca(2+)-dependent signaling through CaM Kinase II (CaMKII) and calcineurin was suggested to contribute to adverse cardiac remodeling. However, the relative importance of CaMKII versus calcineurin for adverse cardiac remodeling remained unclear. METHODS AND RESULTS We generated double-knockout mice (DKO) lacking the 2 cardiac CaMKII genes δ and γ specifically in cardiomyocytes. We show that both CaMKII isoforms contribute redundantly to phosphorylation not only of phospholamban, ryanodine receptor 2, and histone deacetylase 4, but also calcineurin. Under baseline conditions, DKO mice are viable and display neither abnormal Ca(2+) handling nor functional and structural changes. On pathological pressure overload and β-adrenergic stimulation, DKO mice are protected against cardiac dysfunction and interstitial fibrosis. But surprisingly and paradoxically, DKO mice develop cardiac hypertrophy driven by excessive activation of endogenous calcineurin, which is associated with a lack of phosphorylation at the auto-inhibitory calcineurin A site Ser411. Likewise, calcineurin inhibition prevents cardiac hypertrophy in DKO. On exercise performance, DKO mice show an exaggeration of cardiac hypertrophy with increased expression of the calcineurin target gene RCAN1-4 but no signs of adverse cardiac remodeling. CONCLUSIONS We established a mouse model in which CaMKII's activity is specifically and completely abolished. By the use of this model we show that CaMKII induces maladaptive cardiac remodeling while it inhibits calcineurin-dependent hypertrophy. These data suggest inhibition of CaMKII but not calcineurin as a promising approach to attenuate the progression of heart failure.
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Affiliation(s)
- Michael M Kreusser
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.)
| | - Lorenz H Lehmann
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.)
| | - Stanislav Keranov
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.)
| | - Marc-Oscar Hoting
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.)
| | - Ulrike Oehl
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.)
| | - Michael Kohlhaas
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.)
| | - Jan-Christian Reil
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.)
| | - Kay Neumann
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.)
| | - Michael D Schneider
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.)
| | - Joseph A Hill
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.)
| | - Dobromir Dobrev
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.)
| | - Christoph Maack
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.)
| | - Lars S Maier
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.)
| | - Hermann-Josef Gröne
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.)
| | - Hugo A Katus
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.)
| | - Eric N Olson
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.)
| | - Johannes Backs
- From the Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (M.M.K., L.H.L., S.K., M.-O.H., U.O., J.B.); Department of Cardiology, Saarland University, Homburg, Germany (M.K., J.-C.R., C.M.); Department of Internal Medicine II, University of Regensburg, Germany (K.N., L.S.M.); British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom (M.D.S.); Department of Internal Medicine, University of Southwestern Texas Medical Center, Dallas (J.A.H.); Institute of Pharmacology, University of Duisburg-Essen, Germany (D.D.); Department of Molecular Pathology, German Cancer Research Center, Heidelberg, Germany (H.-J.G.); Department of Cardiology, University of Heidelberg, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany (H.A.K.); and the Department of Molecular Biology, University of Southwestern Texas Medical Center, Dallas (E.N.O.).
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Tsuji Y, Ishikawa T, Makita N. Molecular mechanisms of heart failure progression associated with implantable cardioverter-defibrillator shocks for ventricular tachyarrhythmias. J Arrhythm 2014. [DOI: 10.1016/j.joa.2014.04.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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206
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Grandi E, Edwards AG, Herren AW, Bers DM. CaMKII comes of age in cardiac health and disease. Front Pharmacol 2014; 5:154. [PMID: 25071573 PMCID: PMC4080132 DOI: 10.3389/fphar.2014.00154] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 06/12/2014] [Indexed: 11/13/2022] Open
Affiliation(s)
- Eleonora Grandi
- Department of Pharmacology, University of California, Davis Davis, CA, USA
| | - Andrew G Edwards
- Institute for Experimental Medicine, Oslo University Hospital Ullevål Oslo, Norway ; Simula Research Laboratory Lysaker, Norway
| | - Anthony W Herren
- Department of Pharmacology, University of California, Davis Davis, CA, USA
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis Davis, CA, USA
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207
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Vincent KP, McCulloch AD, Edwards AG. Toward a hierarchy of mechanisms in CaMKII-mediated arrhythmia. Front Pharmacol 2014; 5:110. [PMID: 24994983 PMCID: PMC4062880 DOI: 10.3389/fphar.2014.00110] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 04/25/2014] [Indexed: 12/16/2022] Open
Abstract
Calcium/calmodulin-dependent protein kinase II (CaMKII) activity has been shown to contribute to arrhythmogenesis in a remarkably broad range of cardiac pathologies. Several of these involve significant structural and electrophysiologic remodeling, whereas others are due to specific channelopathies, and are not typically associated with arrhythmogenic changes to protein expression or cellular and tissue structure. The ability of CaMKII to contribute to arrhythmia across such a broad range of phenotypes suggests one of two interpretations regarding the role of CaMKII in cardiac arrhythmia: (1) some CaMKII-dependent mechanism is a common driver of arrhythmia irrespective of the specific etiology of the disease, or (2) these different etiologies expose different mechanisms by which CaMKII is capable of promoting arrhythmia. In this review, we dissect the available mechanistic evidence to explore these two possibilities and discuss how the various molecular actions of CaMKII promote arrhythmia in different pathophysiologic contexts.
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Affiliation(s)
- Kevin P Vincent
- Department of Bioengineering, University of California San Diego La Jolla, CA, USA
| | - Andrew D McCulloch
- Department of Bioengineering, University of California San Diego La Jolla, CA, USA ; Department of Medicine, University of California San Diego La Jolla, CA, USA
| | - Andrew G Edwards
- Department of Bioengineering, University of California San Diego La Jolla, CA, USA ; Institute for Experimental Medicine, Oslo University Hospital Ullevål Oslo, Norway ; Simula Research Laboratory Lysaker, Norway
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208
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Biesemann N, Mendler L, Wietelmann A, Hermann S, Schäfers M, Krüger M, Boettger T, Borchardt T, Braun T. Myostatin regulates energy homeostasis in the heart and prevents heart failure. Circ Res 2014; 115:296-310. [PMID: 24807786 DOI: 10.1161/circresaha.115.304185] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Myostatin is a major negative regulator of skeletal muscle mass and initiates multiple metabolic changes, including enhanced insulin sensitivity. However, the function of myostatin in the heart is barely understood, although it is upregulated in the myocardium under several pathological conditions. OBJECTIVE Here, we aimed to decipher the role of myostatin and myostatin-dependent signaling pathways for cardiac function and cardiac metabolism in adult mice. To avoid potential counterregulatory mechanisms occurring in constitutive and germ-line-based myostatin mutants, we generated a mouse model that allows myostatin inactivation in adult cardiomyocytes. METHODS AND RESULTS Cardiac MRI revealed that genetic inactivation of myostatin signaling in the adult murine heart caused cardiac hypertrophy and heart failure, partially recapitulating effects of the age-dependent decline of the myostatin paralog growth and differentiation factor 11. We found that myostatin represses AMP-activated kinase activation in the heart via transforming growth factor-β-activated kinase 1, thereby preventing a metabolic switch toward glycolysis and glycogen accumulation. Furthermore, myostatin stimulated expression of regulator of G-protein signaling 2, a GTPase-activating protein that restricts Gaq and Gas signaling and thereby protects against cardiac failure. Inhibition of AMP-activated kinase in vivo rescued cardiac hypertrophy and prevented enhanced glycolytic flow and glycogen accumulation after inactivation of myostatin in cardiomyocytes. CONCLUSIONS Our results uncover an important role of myostatin in the heart for maintaining cardiac energy homeostasis and preventing cardiac hypertrophy.
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Affiliation(s)
- Nadine Biesemann
- From the Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (N.B., L.M., A.W., M.K., T. Boettger, T. Borchardt, T. Braun); Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Mainz, Germany (N.B.); Institute of Biochemistry, Faculty of General Medicine, University of Szeged, Szeged, Hungary (L.M.); and European Institute for Molecular Imaging, University of Münster, Münster, Germany (S.H., M.S.)
| | - Luca Mendler
- From the Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (N.B., L.M., A.W., M.K., T. Boettger, T. Borchardt, T. Braun); Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Mainz, Germany (N.B.); Institute of Biochemistry, Faculty of General Medicine, University of Szeged, Szeged, Hungary (L.M.); and European Institute for Molecular Imaging, University of Münster, Münster, Germany (S.H., M.S.)
| | - Astrid Wietelmann
- From the Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (N.B., L.M., A.W., M.K., T. Boettger, T. Borchardt, T. Braun); Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Mainz, Germany (N.B.); Institute of Biochemistry, Faculty of General Medicine, University of Szeged, Szeged, Hungary (L.M.); and European Institute for Molecular Imaging, University of Münster, Münster, Germany (S.H., M.S.)
| | - Sven Hermann
- From the Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (N.B., L.M., A.W., M.K., T. Boettger, T. Borchardt, T. Braun); Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Mainz, Germany (N.B.); Institute of Biochemistry, Faculty of General Medicine, University of Szeged, Szeged, Hungary (L.M.); and European Institute for Molecular Imaging, University of Münster, Münster, Germany (S.H., M.S.)
| | - Michael Schäfers
- From the Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (N.B., L.M., A.W., M.K., T. Boettger, T. Borchardt, T. Braun); Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Mainz, Germany (N.B.); Institute of Biochemistry, Faculty of General Medicine, University of Szeged, Szeged, Hungary (L.M.); and European Institute for Molecular Imaging, University of Münster, Münster, Germany (S.H., M.S.)
| | - Marcus Krüger
- From the Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (N.B., L.M., A.W., M.K., T. Boettger, T. Borchardt, T. Braun); Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Mainz, Germany (N.B.); Institute of Biochemistry, Faculty of General Medicine, University of Szeged, Szeged, Hungary (L.M.); and European Institute for Molecular Imaging, University of Münster, Münster, Germany (S.H., M.S.)
| | - Thomas Boettger
- From the Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (N.B., L.M., A.W., M.K., T. Boettger, T. Borchardt, T. Braun); Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Mainz, Germany (N.B.); Institute of Biochemistry, Faculty of General Medicine, University of Szeged, Szeged, Hungary (L.M.); and European Institute for Molecular Imaging, University of Münster, Münster, Germany (S.H., M.S.)
| | - Thilo Borchardt
- From the Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (N.B., L.M., A.W., M.K., T. Boettger, T. Borchardt, T. Braun); Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Mainz, Germany (N.B.); Institute of Biochemistry, Faculty of General Medicine, University of Szeged, Szeged, Hungary (L.M.); and European Institute for Molecular Imaging, University of Münster, Münster, Germany (S.H., M.S.).
| | - Thomas Braun
- From the Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany (N.B., L.M., A.W., M.K., T. Boettger, T. Borchardt, T. Braun); Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Mainz, Germany (N.B.); Institute of Biochemistry, Faculty of General Medicine, University of Szeged, Szeged, Hungary (L.M.); and European Institute for Molecular Imaging, University of Münster, Münster, Germany (S.H., M.S.).
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Abstract
Calcium/calmodulin (Ca2+/CaM) dependent protein kinase II (CaMKII) has emerged as a key nodal protein in the regulation of cardiac physiology and pathology. Due to the particularly elegant relationship between the structure and function of the kinase, CaMKII is able to translate a diverse set of signaling events into downstream physiological effects. While CaMKII is typically autoinhibited at basal conditions, prolonged rapid Ca2+ cycling can activate the kinase and allow post-translational modifications that depend critically on the biochemical environment of the heart. These modifications result in sustained, autonomous CaMKII activation and have been associated with pathological cardiac signaling. Indeed, improved understanding of CaMKII activation mechanisms could potentially lead to new clinical therapies for the treatment or prevention of cardiovascular disease. Here we review the known mechanisms of CaMKII activation and discuss some of the pathological signaling pathways in which they play a role.
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210
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Abstract
It has been persuasively shown in the last two decades that the development of heart failure is closely linked to distinct alterations in Ca(2+) cycling. A crucial point in this respect is an increased spontaneous release of Ca(2+) out of the sarcoplasmic reticulum during diastole via ryanodine receptors type 2 (RyR2). The consequence is a compromised sarcoplasmic reticulum Ca(2+) storage capacity, which impairs systolic contractility and possibly diastolic cardiac function due to Ca(2+) overload. Additionally, leaky RyR2 are more and more regarded to potently induce proarrhythmic triggers. Elimination of spontaneously released Ca(2+) via RyR2 in diastole can cause a transient sarcolemmal inward current and hence delayed after depolarisations as substrate for cardiac arrhythmias. In this article, the pathological role and consequences of the SR Ca(2+)-leak and its regulation are reviewed with a main focus on protein kinase A and Ca(2+)-calmodulin-dependent kinase II. We summarise clinical consequences of "leaky RyR2" as well as possible therapeutic strategies in order to correct RyR2 dysfunction and discuss the significance of the available data.
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211
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Kreusser MM, Backs J. Integrated mechanisms of CaMKII-dependent ventricular remodeling. Front Pharmacol 2014; 5:36. [PMID: 24659967 PMCID: PMC3950490 DOI: 10.3389/fphar.2014.00036] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 02/18/2014] [Indexed: 12/20/2022] Open
Abstract
CaMKII has been shown to be activated during different cardiac pathological processes, and CaMKII-dependent mechanisms contribute to pathological cardiac remodeling, cardiac arrhythmias, and contractile dysfunction during heart failure. Activation of CaMKII during cardiac stress results in a broad number of biological effects such as, on the one hand, acute effects due to phosphorylation of distinct cellular proteins as ion channels and calcium handling proteins and, on the other hand, integrative mechanisms by changing gene expression. This review focuses on transcriptional and epigenetic effects of CaMKII activation during chronic cardiac remodeling. Multiple mechanisms have been described how CaMKII mediates changes in cardiac gene expression. CaMKII has been shown to directly phosphorylate components of the cardiac gene regulation machinery. CaMKII phosphorylates several transcription factors such as CREB that induces the activation of specific gene programs. CaMKII activates transcriptional regulators also indirectly by phosphorylating histone deacetylases, especially HDAC4, which in turn inhibits transcription factors that drive cardiac hypertrophy, fibrosis, and dysfunction. Recent studies demonstrate that CaMKII also phosphorylate directly histones, which may contribute to changes in gene expression. These findings of CaMKII-dependent gene regulation during cardiac remodeling processes suggest novel strategies for CaMKII-dependent “transcriptional or epigenetic therapies” to control cardiac gene expression and function. Manipulation of CaMKII-dependent signaling pathways in the settings of pathological cardiac growth, remodeling, and heart failure represents an auspicious therapeutic approach.
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Affiliation(s)
- Michael M Kreusser
- Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg Heidelberg, Germany ; German Center for Cardiovascular Research (DZHK) Partner Site Heidelberg/Mannheim, Germany
| | - Johannes Backs
- Research Unit Cardiac Epigenetics, Department of Cardiology, University of Heidelberg Heidelberg, Germany ; German Center for Cardiovascular Research (DZHK) Partner Site Heidelberg/Mannheim, Germany
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212
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Reactive oxygen species and excitation-contraction coupling in the context of cardiac pathology. J Mol Cell Cardiol 2014; 73:92-102. [PMID: 24631768 DOI: 10.1016/j.yjmcc.2014.03.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 02/05/2014] [Accepted: 03/01/2014] [Indexed: 01/12/2023]
Abstract
Reactive oxygen species (ROS) are highly reactive oxygen-derived chemical compounds that are by-products of aerobic cellular metabolism as well as crucial second messengers in numerous signaling pathways. In excitation-contraction-coupling (ECC), which links electrical signaling and coordinated cardiac contraction, ROS have a severe impact on several key ion handling proteins such as ion channels and transporters, but also on regulating proteins such as protein kinases (e.g. CaMKII, PKA or PKC), thereby pivotally influencing the delicate balance of this finely tuned system. While essential as second messengers, ROS may be deleterious when excessively produced due to a disturbed balance in Na(+) and Ca(2+) handling, resulting in Na(+) and Ca(2+) overload, SR Ca(2+) loss and contractile dysfunction. This may, in the end, result in systolic and diastolic dysfunction and arrhythmias. This review aims to provide an overview of the single targets of ROS in ECC and to outline the role of ROS in major cardiac pathologies, such as heart failure and arrhythmogenesis. This article is part of a Special Issue entitled "Redox Signalling in the Cardiovascular System"
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213
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CaMKII oxidative activation and the pathogenesis of cardiac disease. J Mol Cell Cardiol 2014; 73:112-6. [PMID: 24530899 DOI: 10.1016/j.yjmcc.2014.02.004] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 02/03/2014] [Accepted: 02/05/2014] [Indexed: 12/22/2022]
Abstract
Calcium and redox signaling both play important roles in the pathogenesis of cardiac disease; although how these signals are integrated in the heart remains unclear. One putative sensor for both calcium and oxidative stress in the heart is CaMKII, a calcium activated kinase that has recently been shown to also be regulated by oxidation. Oxidative activation of CaMKII occurs in several models of cardiac disease, including myocardial injury and inflammation, excessive neurohumoral activation, atrial fibrillation, and sinus node dysfunction. Additionally, oxidative activation of CaMKII is suggested in subcellular domains where calcium and ROS signaling intersect, such as mitochondria. This review describes the mechanism of activation of CaMKII by oxidation, the cardiac diseases where oxidized CaMKII has been identified, and suggests contexts where oxidized CaMKII is likely to play an important role. This article is part of a Special Issue entitled "Redox Signalling in the Cardiovascular System".
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214
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Gray CBB, Heller Brown J. CaMKIIdelta subtypes: localization and function. Front Pharmacol 2014; 5:15. [PMID: 24575042 PMCID: PMC3920101 DOI: 10.3389/fphar.2014.00015] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Accepted: 01/25/2014] [Indexed: 12/28/2022] Open
Abstract
In this review we discuss the localization and function of the known subtypes of calcium/calmodulin dependent protein kinase IIδ (CaMKIIδ) and their role in cardiac physiology and pathophysiology. The CaMKII holoenzyme is comprised of multiple subunits that are encoded by four different genes called CaMKIIα, β, γ, and δ. While these four genes have a high degree of sequence homology, they are expressed in different tissues. CaMKIIα and β are expressed in neuronal tissue while γ and δ are present throughout the body, including in the heart. Both CaMKIIγ and δ are alternatively spliced in the heart to generate multiple subtypes. CaMKIIδ is the predominant cardiac isoform and is alternatively spliced in the heart to generate the CaMKIIδB subtype or the slightly less abundant δC subtype. The CaMKIIδB mRNA sequence contains a 33bp insert not present in δC that codes for an 11-amino acid nuclear localization sequence. This review focuses on the localization and function of the CaMKIIδ subtypes δB and δC and the role of these subtypes in arrhythmias, contractile dysfunction, gene transcription, and the regulation of Ca2+ handling.
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Affiliation(s)
- Charles B B Gray
- Department of Pharmacology, University of California at San Diego, San Diego CA, USA ; Biomedical Sciences Graduate Program, University of California at SanDiego, SanDiego CA, USA
| | - Joan Heller Brown
- Department of Pharmacology, University of California at San Diego, San Diego CA, USA
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215
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Lorenz K, Stathopoulou K, Schmid E, Eder P, Cuello F. Heart failure-specific changes in protein kinase signalling. Pflugers Arch 2014; 466:1151-62. [DOI: 10.1007/s00424-014-1462-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 01/19/2014] [Accepted: 01/22/2014] [Indexed: 01/14/2023]
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216
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Curran J, Tang L, Roof SR, Velmurugan S, Millard A, Shonts S, Wang H, Santiago D, Ahmad U, Perryman M, Bers DM, Mohler PJ, Ziolo MT, Shannon TR. Nitric oxide-dependent activation of CaMKII increases diastolic sarcoplasmic reticulum calcium release in cardiac myocytes in response to adrenergic stimulation. PLoS One 2014; 9:e87495. [PMID: 24498331 PMCID: PMC3911966 DOI: 10.1371/journal.pone.0087495] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 12/26/2013] [Indexed: 11/19/2022] Open
Abstract
Spontaneous calcium waves in cardiac myocytes are caused by diastolic sarcoplasmic reticulum release (SR Ca(2+) leak) through ryanodine receptors. Beta-adrenergic (β-AR) tone is known to increase this leak through the activation of Ca-calmodulin-dependent protein kinase (CaMKII) and the subsequent phosphorylation of the ryanodine receptor. When β-AR drive is chronic, as observed in heart failure, this CaMKII-dependent effect is exaggerated and becomes potentially arrhythmogenic. Recent evidence has indicated that CaMKII activation can be regulated by cellular oxidizing agents, such as reactive oxygen species. Here, we investigate how the cellular second messenger, nitric oxide, mediates CaMKII activity downstream of the adrenergic signaling cascade and promotes the generation of arrhythmogenic spontaneous Ca(2+) waves in intact cardiomyocytes. Both SCaWs and SR Ca(2+) leak were measured in intact rabbit and mouse ventricular myocytes loaded with the Ca-dependent fluorescent dye, fluo-4. CaMKII activity in vitro and immunoblotting for phosphorylated residues on CaMKII, nitric oxide synthase, and Akt were measured to confirm activity of these enzymes as part of the adrenergic cascade. We demonstrate that stimulation of the β-AR pathway by isoproterenol increased the CaMKII-dependent SR Ca(2+) leak. This increased leak was prevented by inhibition of nitric oxide synthase 1 but not nitric oxide synthase 3. In ventricular myocytes isolated from wild-type mice, isoproterenol stimulation also increased the CaMKII-dependent leak. Critically, in myocytes isolated from nitric oxide synthase 1 knock-out mice this effect is ablated. We show that isoproterenol stimulation leads to an increase in nitric oxide production, and nitric oxide alone is sufficient to activate CaMKII and increase SR Ca(2+) leak. Mechanistically, our data links Akt to nitric oxide synthase 1 activation downstream of β-AR stimulation. Collectively, this evidence supports the hypothesis that CaMKII is regulated by nitric oxide as part of the adrenergic cascade leading to arrhythmogenesis.
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Affiliation(s)
- Jerry Curran
- Davis Heart and Lung Research Institute, Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Lifei Tang
- Davis Heart and Lung Research Institute, Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Steve R. Roof
- Davis Heart and Lung Research Institute, Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Sathya Velmurugan
- Department of Molecular Biophysics and Physiology, Rush University, Chicago, Illinois, United States of America
| | - Ashley Millard
- Department of Molecular Biophysics and Physiology, Rush University, Chicago, Illinois, United States of America
| | - Stephen Shonts
- Department of Molecular Biophysics and Physiology, Rush University, Chicago, Illinois, United States of America
| | - Honglan Wang
- Davis Heart and Lung Research Institute, Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Demetrio Santiago
- Department of Molecular Biophysics and Physiology, Rush University, Chicago, Illinois, United States of America
| | - Usama Ahmad
- Department of Molecular Biophysics and Physiology, Rush University, Chicago, Illinois, United States of America
| | - Matthew Perryman
- Department of Molecular Biophysics and Physiology, Rush University, Chicago, Illinois, United States of America
| | - Donald M. Bers
- Department of Pharmacology, University of California Davis, Davis, California, United States of America
| | - Peter J. Mohler
- Davis Heart and Lung Research Institute, Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Mark T. Ziolo
- Davis Heart and Lung Research Institute, Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail: (MTZ); (TRS)
| | - Thomas R. Shannon
- Department of Molecular Biophysics and Physiology, Rush University, Chicago, Illinois, United States of America
- * E-mail: (MTZ); (TRS)
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217
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Huang C, Cao W, Liao R, Wang J, Wang Y, Tong L, Chen X, Zhu W, Zhang W. PP1γ functionally augments the alternative splicing of CaMKIIδ through interaction with ASF. Am J Physiol Cell Physiol 2014; 306:C167-77. [DOI: 10.1152/ajpcell.00145.2013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Protein phosphatase 1 (PP1) and Ca2+/calmodulin-dependent protein kinase δ (CaMKIIδ) are upregulated in heart disorders. Alternative splicing factor (ASF), a major splice factor for CaMKIIδ splicing, can be regulated by both protein kinase and phosphatase. Here we determine the role of PP1 isoforms in ASF-mediated splicing of CaMKIIδ in cells. We found that 1) PP1γ, but not α or β isoform, enhanced the splicing of CaMKIIδ in HEK293T cells; 2) PP1γ promoted the function of ASF, evidenced by the existence of ASF-PP1γ association as well as the PP1γ overexpression- or silencing-mediated change in CaMKIIδ splicing in ASF-transfected HEK293T cells; 3) CaMKIIδ splicing was promoted by overexpression of PP1γ and impaired by application of PP1 inhibitor 1 (I1PP1) or pharmacological inhibitor tautomycetin in primary cardiomyocytes; 4) CaMKIIδ splicing and enhancement of ASF-PP1γ association induced by oxygen-glucose deprivation followed by reperfusion (OGD/R) were potentiated by overexpression of PP1γ and suppressed by inhibition of PP1γ with I1PP1 or tautomycetin in primary cardiomyocytes; 5) functionally, overexpression and inhibition of PP1γ, respectively, potentiated or suppressed the apoptosis and Bax/Bcl-2 ratio, which were associated with the enhanced activity of CaMKII in OGD/R-stimulated cardiomyocytes; and 6) CaMKII was required for the OGD/R induced- and PP1γ exacerbated-apoptosis of cardiomyocytes, evidenced by a specific inhibitor of CaMKII KN93, but not its structural analog KN92, attenuating the apoptosis and Bax/Bcl-2 ratio in OGD/R and PP1γ-treated cells. In conclusion, our results show that PP1γ promotes the alternative splicing of CaMKIIδ through its interacting with ASF, exacerbating OGD/R-triggered apoptosis in primary cardiomyocytes.
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Affiliation(s)
- Chao Huang
- Department of Pharmacology, School of Medicine, Nantong University, Nantong, China
| | - Wenwen Cao
- Department of Pharmacology, School of Medicine, Nantong University, Nantong, China
| | - Rujia Liao
- Department of Pharmacology, School of Medicine, Nantong University, Nantong, China
| | - Jia Wang
- Department of Pharmacology, School of Medicine, Nantong University, Nantong, China
| | - Yuzhe Wang
- Department of Pharmacology, School of Medicine, Nantong University, Nantong, China
| | - Lijuan Tong
- Department of Pharmacology, School of Medicine, Nantong University, Nantong, China
| | - Xiangfan Chen
- Department of Pharmacology, School of Medicine, Nantong University, Nantong, China
| | - Weizhong Zhu
- Cardiovascular Research Center, School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Wei Zhang
- Department of Pharmacology, School of Medicine, Nantong University, Nantong, China
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218
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Tilley DG, Rockman HA. Role of β-adrenergic receptor signaling and desensitization in heart failure: new concepts and prospects for treatment. Expert Rev Cardiovasc Ther 2014; 4:417-32. [PMID: 16716102 DOI: 10.1586/14779072.4.3.417] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The use of beta-blockers to antagonize beta-adrenergic receptor signaling in the heart has become a standard method of treatment for heart failure, resulting in positive clinical outcomes alone and in conjunction with other modulators of cardiomyocyte contractility. However, an entire explanation for improved cardiac function in patients using beta-blockers is unknown, and in fact may be quite complicated, considering the numerous intracellular signaling pathways associated with beta-adrenergic receptors. Stimulation of beta-adrenergic receptors during both normal conditions and during heart failure activate several distinct signaling cascades, which influence cardiomyocyte contraction, hypertrophy and apoptosis. This review explores the signaling cascades induced by beta-adrenergic receptor activation in normal and desensitized states to provide new insight into the effective treatment of cardiac dysfunction.
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Affiliation(s)
- Douglas G Tilley
- Department of Medicine Duke University Medical Center Durham, NC 27710, USA.
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219
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Sankar N, deTombe PP, Mignery GA. Calcineurin-NFATc regulates type 2 inositol 1,4,5-trisphosphate receptor (InsP3R2) expression during cardiac remodeling. J Biol Chem 2014; 289:6188-98. [PMID: 24415751 DOI: 10.1074/jbc.m113.495242] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
In heart, the type 2 inositol 1,4,5-triphosphate receptor (InsP3R2) is the predominant isoform expressed and is localized in the nuclear membrane of ventricular myocytes. InsP3R2-mediated Ca(2+) release regulates hypertrophy specific gene expression by modulating CaMKIIδ, histone deacetylase, and calcineurin-NFATc signaling pathways. InsP3R2 protein is a hypertrophy specific marker and is overexpressed in heart failure animal models and in humans. However, the regulation of InsP3R2 mRNA and protein expression during cardiac hypertrophy and heart failure is not known. Here we show the transcriptional regulation of the Itpr2 gene in adult cardiomyocytes. Our data demonstrates that, InsP3R2 mRNA and protein expression is activated by hypertrophic agonists and attenuated by InsP3R inhibitors 2-aminoethoxyldiphenyl borate and xestospongin-C. The Itpr2 promoter is regulated by the calcineurin-NFATc signaling pathway. NFATc1 regulates Itpr2 gene expression by directly binding to the Itpr2 promoter. The calcineurin-NFATc mediated up-regulation of the Itpr2 promoter was attenuated by cyclosporine-A. InsP3R2 mRNA and protein expression was up-regulated in calcineurin-A transgenic mice and in human heart failure. Collectively, our data suggests that ITPR2 and hypertrophy specific gene expression is regulated, in part, by a positive feedback regulation between InsP3R2 and calcineurin-NFATc signaling pathways.
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Affiliation(s)
- Natesan Sankar
- From the Department of Cell & Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois 60153
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220
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Fiedler LR, Maifoshie E, Schneider MD. Mouse models of heart failure: cell signaling and cell survival. Curr Top Dev Biol 2014; 109:171-247. [PMID: 24947238 DOI: 10.1016/b978-0-12-397920-9.00002-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Heart failure is one of the paramount global causes of morbidity and mortality. Despite this pandemic need, the available clinical counter-measures have not altered substantially in recent decades, most notably in the context of pharmacological interventions. Cell death plays a causal role in heart failure, and its inhibition poses a promising approach that has not been thoroughly explored. In previous approaches to target discovery, clinical failures have reflected a deficiency in mechanistic understanding, and in some instances, failure to systematically translate laboratory findings toward the clinic. Here, we review diverse mouse models of heart failure, with an emphasis on those that identify potential targets for pharmacological inhibition of cell death, and on how their translation into effective therapies might be improved in the future.
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Affiliation(s)
- Lorna R Fiedler
- British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Imperial College London, London, UK.
| | - Evie Maifoshie
- British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Imperial College London, London, UK
| | - Michael D Schneider
- British Heart Foundation Centre of Research Excellence, National Heart and Lung Institute, Imperial College London, London, UK.
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221
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Association of genetic variation in calmodulin and left ventricular mass in full-term newborns. Int J Genomics 2013; 2013:410407. [PMID: 24298550 PMCID: PMC3835711 DOI: 10.1155/2013/410407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 09/20/2013] [Indexed: 11/18/2022] Open
Abstract
Calmodulin II (CALM2) gene polymorphism might be responsible for the variation in the left ventricular mass amongst healthy individuals. The aim was to evaluate the correlation between left ventricular mass (LVM) and g.474955027G>A (rs7565161) polymorphism adjacent to the CALM2 gene. Healthy Polish newborns (n = 206) were recruited. Two-dimensional M-mode echocardiography was used to assess LVM. Polymorphisms were determined by polymerase chain reaction-restriction fragment length polymorphism and sequencing analyses. The carriers of the G allele of the CALM2 polymorphism had significantly higher left ventricular mass/weight (LVM/BW) values, when compared with newborns homozygous for the A allele (3.1 g/m(2) versus 2.5 g/m(2), P adjusted = 0.036). The AG genotype of CALM2 was associated with the highest values of LVM/BW, exhibiting a pattern of overdominance (2.9 g/kg versus 3.1 g/kg versus 2.5 g/kg, P adjusted = 0.037). The results of this study suggest that G>A CALM2 polymorphism may account for subtle variation in LVM at birth.
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222
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Abstract
Ca²⁺ plays a crucial role in connecting membrane excitability with contraction in myocardium. The hallmark features of heart failure are mechanical dysfunction and arrhythmias; defective intracellular Ca²⁺ homeostasis is a central cause of contractile dysfunction and arrhythmias in failing myocardium. Defective Ca²⁺ homeostasis in heart failure can result from pathological alteration in the expression and activity of an increasingly understood collection of Ca²⁺ homeostatic and structural proteins, ion channels, and enzymes. This review focuses on the molecular mechanisms of defective Ca²⁺ cycling in heart failure and considers how fundamental understanding of these pathways may translate into novel and innovative therapies.
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Affiliation(s)
- Min Luo
- Division of Cardiovascular Medicine, Department of Internal Medicine, Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
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223
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Ho HT, Liu B, Snyder JS, Lou Q, Brundage EA, Velez-Cortes F, Wang H, Ziolo MT, Anderson ME, Sen CK, Wehrens XHT, Fedorov VV, Biesiadecki BJ, Hund TJ, Györke S. Ryanodine receptor phosphorylation by oxidized CaMKII contributes to the cardiotoxic effects of cardiac glycosides. Cardiovasc Res 2013; 101:165-74. [PMID: 24104877 DOI: 10.1093/cvr/cvt233] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
AIMS Recent studies suggest that proarrhythmic effects of cardiac glycosides (CGs) on cardiomyocyte Ca(2+) handling involve generation of reactive oxygen species (ROS). However, the specific pathway(s) of ROS production and the subsequent downstream molecular events that mediate CG-dependent arrhythmogenesis remain to be defined. METHODS AND RESULTS We examined the effects of digitoxin (DGT) on Ca(2+) handling and ROS production in cardiomyocytes using a combination of pharmacological approaches and genetic mouse models. Myocytes isolated from mice deficient in NADPH oxidase type 2 (NOX2KO) and mice transgenically overexpressing mitochondrial superoxide dismutase displayed markedly increased tolerance to the proarrhythmic action of DGT as manifested by the inhibition of DGT-dependent ROS and spontaneous Ca(2+) waves (SCW). Additionally, DGT-induced mitochondrial membrane potential depolarization was abolished in NOX2KO cells. DGT-dependent ROS was suppressed by the inhibition of PI3K, PKC, and the mitochondrial KATP channel, suggesting roles for these proteins, respectively, in activation of NOX2 and in mitochondrial ROS generation. Western blot analysis revealed increased levels of oxidized CaMKII in WT but not in NOX2KO hearts treated with DGT. The DGT-induced increase in SCW frequency was abolished in myocytes isolated from mice in which the Ser 2814 CaMKII phosphorylation site on RyR2 is constitutively inactivated. CONCLUSION These results suggest that the arrhythmogenic adverse effects of CGs on Ca(2+) handling involve PI3K- and PKC-mediated stimulation of NOX2 and subsequent NOX2-dependent ROS release from the mitochondria; mitochondria-derived ROS then activate CaMKII with consequent phosphorylation of RyR2 at Ser 2814.
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Affiliation(s)
- Hsiang-Ting Ho
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
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224
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Erickson JR, Pereira L, Wang L, Han G, Ferguson A, Dao K, Copeland RJ, Despa F, Hart GW, Ripplinger CM, Bers DM. Diabetic hyperglycaemia activates CaMKII and arrhythmias by O-linked glycosylation. Nature 2013; 502:372-6. [PMID: 24077098 PMCID: PMC3801227 DOI: 10.1038/nature12537] [Citation(s) in RCA: 455] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 08/12/2013] [Indexed: 01/26/2023]
Abstract
Ca2+-Calmodulin dependent protein kinase II (CaMKII) is a regulatory node in heart and brain, and its chronic activation can be pathological. CaMKII activation seen in heart failure can directly induce pathological changes in ion channels, Ca2+ handling and gene transcription.1 Here we discover a novel mechanism linking CaMKII and hyperglycemic signaling in diabetes mellitus, which is a key risk factor for heart2 and neurodegenerative diseases.3,4 Acute hyperglycemia causes covalent modification of CaMKII by O-linked N-acetylglucosamine (O-GlcNAc). O-GlcNAc modification of CaMKII at Ser-279 activates CaMKII autonomously, creating molecular memory even after [Ca2+] declines. O-GlcNAc modified CaMKII is increased in heart and brain from diabetic humans and rats. In cardiomyocytes, increased [glucose] significantly enhances CaMKII-dependent activation of spontaneous sarcoplasmic reticulum (SR) Ca2+ release events that can contribute to cardiac mechanical dysfunction and arrhythmias.1 These effects were prevented by pharmacological inhibition of O-GlcNAc signaling or genetic ablation of CaMKIIδ. In intact perfused hearts, arrhythmias were enhanced by increased [glucose] via O-GlcNAc-and CaMKII-dependent pathways. In diabetic animals, acute blockade of O-GlcNAc inhibited arrhythmogenesis. Thus, O-GlcNAc modification of CaMKII is a novel signaling event in pathways that may contribute critically to cardiac and neuronal pathophysiology in diabetes and other diseases.
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Affiliation(s)
- Jeffrey R Erickson
- Department of Pharmacology, University of California, Davis, Davis, California 95616, USA
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225
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Pereira RO, Wende AR, Olsen C, Soto J, Rawlings T, Zhu Y, Anderson SM, Abel ED. Inducible overexpression of GLUT1 prevents mitochondrial dysfunction and attenuates structural remodeling in pressure overload but does not prevent left ventricular dysfunction. J Am Heart Assoc 2013; 2:e000301. [PMID: 24052497 PMCID: PMC3835233 DOI: 10.1161/jaha.113.000301] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Increased glucose transporter 1 (GLUT1) expression and glucose utilization that accompany pressure overload-induced hypertrophy (POH) are believed to be cardioprotective. Moreover, it has been shown that lifelong transgenic overexpression of GLUT1 in the heart prevents cardiac dysfunction after aortic constriction. The relevance of this model to clinical practice is unclear because of the life-long duration of increased glucose metabolism. Therefore, we sought to determine if a short-term increase in GLUT1-mediated myocardial glucose uptake would still confer cardioprotection if overexpression occurred at the onset of POH. METHODS AND RESULTS Mice with cardiomyocyte-specific inducible overexpression of a hemagglutinin (HA)-tagged GLUT1 transgene (G1HA) and their controls (Cont) were subjected to transverse aortic constriction (TAC) 2 days after transgene induction with doxycycline (DOX). Analysis was performed 4 weeks after TAC. Mitochondrial function, adenosine triphosphate (ATP) synthesis, and mRNA expression of oxidative phosphorylation (OXPHOS) genes were reduced in Cont mice, but were maintained in concert with increased glucose utilization in G1HA following TAC. Despite attenuated adverse remodeling in G1HA relative to control TAC mice, cardiac hypertrophy was exacerbated in these mice, and positive dP/dt (in vivo) and cardiac power (ex vivo) were equivalently decreased in Cont and G1HA TAC mice compared to shams, consistent with left ventricular dysfunction. O-GlcNAcylation of Ca2+ cycling proteins was increased in G1HA TAC hearts. CONCLUSIONS Short-term cardiac specific induction of GLUT1 at the onset of POH preserves mitochondrial function and attenuates pathological remodeling, but exacerbates the hypertrophic phenotype and is insufficient to prevent POH-induced cardiac contractile dysfunction, possibly due to impaired calcium cycling.
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Affiliation(s)
- Renata O Pereira
- Division of Endocrinology, Metabolism and Diabetes, and Program in Molecular Medicine, University of Utah School of Medicine, Salt Lake City, UT
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226
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Purohit A, Rokita AG, Guan X, Chen B, Koval OM, Voigt N, Neef S, Sowa T, Gao Z, Luczak ED, Stefansdottir H, Behunin AC, Li N, El-Accaoui RN, Yang B, Swaminathan PD, Weiss RM, Wehrens XHT, Song LS, Dobrev D, Maier LS, Anderson ME. Oxidized Ca(2+)/calmodulin-dependent protein kinase II triggers atrial fibrillation. Circulation 2013; 128:1748-57. [PMID: 24030498 DOI: 10.1161/circulationaha.113.003313] [Citation(s) in RCA: 237] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Atrial fibrillation (AF) is a growing public health problem without adequate therapies. Angiotensin II and reactive oxygen species are validated risk factors for AF in patients, but the molecular pathways connecting reactive oxygen species and AF are unknown. The Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) has recently emerged as a reactive oxygen species-activated proarrhythmic signal, so we hypothesized that oxidized CaMKIIδ could contribute to AF. METHODS AND RESULTS We found that oxidized CaMKII was increased in atria from AF patients compared with patients in sinus rhythm and from mice infused with angiotensin II compared with mice infused with saline. Angiotensin II-treated mice had increased susceptibility to AF compared with saline-treated wild-type mice, establishing angiotensin II as a risk factor for AF in mice. Knock-in mice lacking critical oxidation sites in CaMKIIδ (MM-VV) and mice with myocardium-restricted transgenic overexpression of methionine sulfoxide reductase A, an enzyme that reduces oxidized CaMKII, were resistant to AF induction after angiotensin II infusion. CONCLUSIONS Our studies suggest that CaMKII is a molecular signal that couples increased reactive oxygen species with AF and that therapeutic strategies to decrease oxidized CaMKII may prevent or reduce AF.
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Affiliation(s)
- Anil Purohit
- Department of Internal Medicine, Division of Cardiovascular Medicine and Cardiovascular Research Center, Carver College of Medicine (A.P., A.G.R., X.G., B.C., O.M.K., Z.G., E.D.L., H.S., A.C.B., R.N.E.-A., P.D.S., R.M.W., L.-S.S., M.E.A.), Department of Obstetrics and Gynecology (B.Y.), and Department of Molecular Physiology and Biophysics (M.E.A.), University of Iowa, Iowa City; Institute of Pharmacology, Faculty of Medicine, University Duisburg-Essen, Essen, Germany, and Division of Experimental Cardiology, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany (N.V., D.D.); Cardiology and Pneumology, German Heart Center, University Hospital Goettingen, Goettingen, Germany (S.N., T.S., L.S.M.); and Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX (N.L., X.H.T.W.)
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227
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Krishna A, Valderrábano M, Palade PT, Clark JW. Rate-dependent Ca2+ signalling underlying the force-frequency response in rat ventricular myocytes: a coupled electromechanical modeling study. Theor Biol Med Model 2013; 10:54. [PMID: 24020888 PMCID: PMC3848742 DOI: 10.1186/1742-4682-10-54] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 06/03/2013] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Rate-dependent effects on the Ca2+ sub-system in a rat ventricular myocyte are investigated. Here, we employ a deterministic mathematical model describing various Ca2+ signalling pathways under voltage clamp (VC) conditions, to better understand the important role of calmodulin (CaM) in modulating the key control variables Ca2+/calmodulin-dependent protein kinase-II (CaMKII), calcineurin (CaN), and cyclic adenosine monophosphate (cAMP) as they affect various intracellular targets. In particular, we study the frequency dependence of the peak force generated by the myofilaments, the force-frequency response (FFR). METHODS Our cell model incorporates frequency-dependent CaM-mediated spatially heterogenous interaction of CaMKII and CaN with their principal targets (dihydropyridine (DHPR) and ryanodine (RyR) receptors and the SERCA pump). It also accounts for the rate-dependent effects of phospholamban (PLB) on the SERCA pump; the rate-dependent role of cAMP in up-regulation of the L-type Ca2+ channel (ICa,L); and the enhancement in SERCA pump activity via phosphorylation of PLB. RESULTS Our model reproduces positive peak FFR observed in rat ventricular myocytes during voltage-clamp studies both in the presence/absence of cAMP mediated β-adrenergic stimulation. This study provides quantitative insight into the rate-dependence of Ca2+-induced Ca2+-release (CICR) by investigating the frequency-dependence of the trigger current (ICa,L) and RyR-release. It also highlights the relative role of the sodium-calcium exchanger (NCX) and the SERCA pump at higher frequencies, as well as the rate-dependence of sarcoplasmic reticulum (SR) Ca2+ content. A rigorous Ca2+ balance imposed on our investigation of these Ca2+ signalling pathways clarifies their individual roles. Here, we present a coupled electromechanical study emphasizing the rate-dependence of isometric force developed and also investigate the temperature-dependence of FFR. CONCLUSIONS Our model provides mechanistic biophysically based explanations for the rate-dependence of CICR, generating useful and testable hypotheses. Although rat ventricular myocytes exhibit a positive peak FFR in the presence/absence of beta-adrenergic stimulation, they show a characteristic increase in the positive slope in FFR due to the presence of Norepinephrine or Isoproterenol. Our study identifies cAMP-mediated stimulation, and rate-dependent CaMKII-mediated up-regulation of ICa,L as the key mechanisms underlying the aforementioned positive FFR.
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Affiliation(s)
- Abhilash Krishna
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas, USA
| | - Miguel Valderrábano
- Methodist Hospital Research Institute, Methodist DeBakey Heart & Vascular Center, Houston, Texas, USA
| | - Philip T Palade
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - John W Clark
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas, USA
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228
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Awad S, Kunhi M, Little GH, Bai Y, An W, Bers D, Kedes L, Poizat C. Nuclear CaMKII enhances histone H3 phosphorylation and remodels chromatin during cardiac hypertrophy. Nucleic Acids Res 2013; 41:7656-72. [PMID: 23804765 PMCID: PMC3763528 DOI: 10.1093/nar/gkt500] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Calcium/calmodulin-dependent protein kinase II (CaMKII) plays a central role in pathological cardiac hypertrophy, but the mechanisms by which it modulates gene activity in the nucleus to mediate hypertrophic signaling remain unclear. Here, we report that nuclear CaMKII activates cardiac transcription by directly binding to chromatin and regulating the phosphorylation of histone H3 at serine-10. These specific activities are demonstrated both in vitro and in primary neonatal rat cardiomyocytes. Activation of CaMKII signaling by hypertrophic agonists increases H3 phosphorylation in primary cardiac cells and is accompanied by concomitant cellular hypertrophy. Conversely, specific silencing of nuclear CaMKII using RNA interference reduces both H3 phosphorylation and cellular hypertrophy. The hyper-phosphorylation of H3 associated with increased chromatin binding of CaMKII occurs at specific gene loci reactivated during cardiac hypertrophy. Importantly, H3 Ser-10 phosphorylation and CaMKII recruitment are associated with increased chromatin accessibility and are required for chromatin-mediated transcription of the Mef2 transcription factor. Unlike phosphorylation of H3 by other kinases, which regulates cellular proliferation and immediate early gene activation, CaMKII-mediated signaling to H3 is associated with hypertrophic growth. These observations reveal a previously unrecognized function of CaMKII as a kinase signaling to histone H3 and remodeling chromatin. They suggest a new epigenetic mechanism controlling cardiac hypertrophy.
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Affiliation(s)
- Salma Awad
- Cardiovascular Research Program, King Faisal Specialist Hospital and Research Centre, PO Box 3354, Riyadh 11211, Kingdom of Saudi Arabia, Institute for Genetic Medicine, University of Southern California 2250 Alcazar Street, Los Angeles, CA 90033, USA, Department of Biochemistry and Molecular Biology, University of Southern California 2250 Alcazar Street, Los Angeles, CA 90089, USA, Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA and Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA
| | - Muhammad Kunhi
- Cardiovascular Research Program, King Faisal Specialist Hospital and Research Centre, PO Box 3354, Riyadh 11211, Kingdom of Saudi Arabia, Institute for Genetic Medicine, University of Southern California 2250 Alcazar Street, Los Angeles, CA 90033, USA, Department of Biochemistry and Molecular Biology, University of Southern California 2250 Alcazar Street, Los Angeles, CA 90089, USA, Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA and Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA
| | - Gillian H. Little
- Cardiovascular Research Program, King Faisal Specialist Hospital and Research Centre, PO Box 3354, Riyadh 11211, Kingdom of Saudi Arabia, Institute for Genetic Medicine, University of Southern California 2250 Alcazar Street, Los Angeles, CA 90033, USA, Department of Biochemistry and Molecular Biology, University of Southern California 2250 Alcazar Street, Los Angeles, CA 90089, USA, Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA and Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA
| | - Yan Bai
- Cardiovascular Research Program, King Faisal Specialist Hospital and Research Centre, PO Box 3354, Riyadh 11211, Kingdom of Saudi Arabia, Institute for Genetic Medicine, University of Southern California 2250 Alcazar Street, Los Angeles, CA 90033, USA, Department of Biochemistry and Molecular Biology, University of Southern California 2250 Alcazar Street, Los Angeles, CA 90089, USA, Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA and Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA
| | - Woojin An
- Cardiovascular Research Program, King Faisal Specialist Hospital and Research Centre, PO Box 3354, Riyadh 11211, Kingdom of Saudi Arabia, Institute for Genetic Medicine, University of Southern California 2250 Alcazar Street, Los Angeles, CA 90033, USA, Department of Biochemistry and Molecular Biology, University of Southern California 2250 Alcazar Street, Los Angeles, CA 90089, USA, Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA and Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA
| | - Donald Bers
- Cardiovascular Research Program, King Faisal Specialist Hospital and Research Centre, PO Box 3354, Riyadh 11211, Kingdom of Saudi Arabia, Institute for Genetic Medicine, University of Southern California 2250 Alcazar Street, Los Angeles, CA 90033, USA, Department of Biochemistry and Molecular Biology, University of Southern California 2250 Alcazar Street, Los Angeles, CA 90089, USA, Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA and Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA
| | - Larry Kedes
- Cardiovascular Research Program, King Faisal Specialist Hospital and Research Centre, PO Box 3354, Riyadh 11211, Kingdom of Saudi Arabia, Institute for Genetic Medicine, University of Southern California 2250 Alcazar Street, Los Angeles, CA 90033, USA, Department of Biochemistry and Molecular Biology, University of Southern California 2250 Alcazar Street, Los Angeles, CA 90089, USA, Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA and Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA
| | - Coralie Poizat
- Cardiovascular Research Program, King Faisal Specialist Hospital and Research Centre, PO Box 3354, Riyadh 11211, Kingdom of Saudi Arabia, Institute for Genetic Medicine, University of Southern California 2250 Alcazar Street, Los Angeles, CA 90033, USA, Department of Biochemistry and Molecular Biology, University of Southern California 2250 Alcazar Street, Los Angeles, CA 90089, USA, Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA and Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA,*To whom correspondence should be addressed. Tel: +966 1 464 7272 (ext. 32984); Fax: +966 1 464 7858; or
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229
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Greco AA, Gomez G. Differential effects of hypoxic and hyperoxic stress-induced hypertrophy in cultured chick fetal cardiac myocytes. In Vitro Cell Dev Biol Anim 2013; 50:129-38. [PMID: 23990386 DOI: 10.1007/s11626-013-9684-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 08/11/2013] [Indexed: 11/25/2022]
Abstract
The adult heart responds to contraction demands by hypertrophy, or enlargement, of cardiac myocytes. Adaptive hypertrophy can occur in response to hyperoxic conditions such as exercise, while pathological factors that result in hypoxia ultimately result in heart failure. The difference in the outcomes produced by pathologically versus physiologically induced hypertrophy suggests that the cellular signaling pathways or conditions of myocytes may be different at the cellular level. The structural and functional changes in myocytes resulting from hyperoxia (simulated using hydrogen peroxide) and hypoxia (using oxygen deprivation) were tested on fetal chick cardiac myocytes grown in vitro. Structural changes were measured using immunostaining for α-sarcomeric actin or MyoD, while functional changes were assessed using immunostaining for calcium/calmodulin-dependent kinase (CaMKII) and by measuring intracellular calcium fluxes using live cell fluorescence imaging. Both hypoxic and hyperoxic stress resulted in an upregulation of actin and MyoD expression. Similarly, voltage-gated channels governing myocyte depolarization and the regulation of CaMK were unchanged by hyperoxic or hypoxic conditions. However, the dynamic features of calcium fluxes elicited by caffeine or epinephrine were different in cells subjected to hypoxia versus hyperoxia, suggesting that these different conditions differentially affect components of ligand-activated signaling pathways that regulate calcium. Our results suggest that changes in signaling pathways, rather than structural organization, may mediate the different outcomes associated with hyperoxia-induced versus hypoxia-induced hypertrophy, and these changes are likely initiated at the cellular level.
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Affiliation(s)
- Allison A Greco
- Biology Department, University of Scranton, LSC 395, 204 Monroe Avenue, Scranton, PA, 18510, USA
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230
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Fischer TH, Herting J, Tirilomis T, Renner A, Neef S, Toischer K, Ellenberger D, Förster A, Schmitto JD, Gummert J, Schöndube FA, Hasenfuss G, Maier LS, Sossalla S. Ca
2+
/Calmodulin-Dependent Protein Kinase II and Protein Kinase A Differentially Regulate Sarcoplasmic Reticulum Ca
2+
Leak in Human Cardiac Pathology. Circulation 2013; 128:970-81. [DOI: 10.1161/circulationaha.113.001746] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Sarcoplasmic reticulum (SR) Ca
2+
leak through ryanodine receptor type 2 (RyR2) dysfunction is of major pathophysiological relevance in human heart failure (HF); however, mechanisms underlying progressive RyR2 dysregulation from cardiac hypertrophy to HF are still controversial.
Methods and Results—
We investigated healthy control myocardium (n=5) and myocardium from patients with compensated hypertrophy (n=25) and HF (n=32). In hypertrophy, Ca
2+
/calmodulin-dependent protein kinase II (CaMKII) and protein kinase A (PKA) both phosphorylated RyR2 at levels that were not different from healthy myocardium. Accordingly, inhibitors of these kinases reduced the SR Ca
2+
leak. In HF, however, the SR Ca
2+
leak was nearly doubled compared with hypertrophy, which led to reduced systolic Ca
2+
transients, a depletion of SR Ca
2+
storage and elevated diastolic Ca
2+
levels. This was accompanied by a significantly increased CaMKII-dependent phosphorylation of RyR2. In contrast, PKA-dependent RyR2 phosphorylation was not increased in HF and was independent of previous β-blocker treatment. In HF, CaMKII inhibition but not inhibition of PKA yielded a reduction of the SR Ca
2+
leak. Moreover, PKA inhibition further reduced SR Ca
2+
load and systolic Ca
2+
transients.
Conclusions—
In human hypertrophy, both CaMKII and PKA functionally regulate RyR2 and may induce SR Ca
2+
leak. In the transition from hypertrophy to HF, the diastolic Ca
2+
leak increases and disturbed Ca
2+
cycling occurs. This is associated with an increase in CaMKII- but not PKA-dependent RyR2 phosphorylation. CaMKII inhibition may thus reflect a promising therapeutic target for the treatment of arrhythmias and contractile dysfunction.
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Affiliation(s)
- Thomas H. Fischer
- From Abteilung Kardiologie und Pneumologie/Herzzentrum (T.H.F., J.H., S.N., K.T., A.F., G.H., L.S.M., S.S.), Abteilung Thorax, Herz, Gefäßchirurgie/Herzzentrum (T.T., F.A.S.), and Abteilung Medizinische Statistik (D.E.), Georg August Universität Göttingen, Göttingen, Germany; Abteilung Thorax, Herz, Gefäßchirurgie, Herz und Diabeteszentrum Nordrheinwestfalen, Bad Oeynhausen, Germany (A.R., J.G.); Abteilung Herz, Thorax, Gefäßchirurgie und Transplantationschirurgie, Medizinische Hochschule Hannover,
| | - Jonas Herting
- From Abteilung Kardiologie und Pneumologie/Herzzentrum (T.H.F., J.H., S.N., K.T., A.F., G.H., L.S.M., S.S.), Abteilung Thorax, Herz, Gefäßchirurgie/Herzzentrum (T.T., F.A.S.), and Abteilung Medizinische Statistik (D.E.), Georg August Universität Göttingen, Göttingen, Germany; Abteilung Thorax, Herz, Gefäßchirurgie, Herz und Diabeteszentrum Nordrheinwestfalen, Bad Oeynhausen, Germany (A.R., J.G.); Abteilung Herz, Thorax, Gefäßchirurgie und Transplantationschirurgie, Medizinische Hochschule Hannover,
| | - Theodor Tirilomis
- From Abteilung Kardiologie und Pneumologie/Herzzentrum (T.H.F., J.H., S.N., K.T., A.F., G.H., L.S.M., S.S.), Abteilung Thorax, Herz, Gefäßchirurgie/Herzzentrum (T.T., F.A.S.), and Abteilung Medizinische Statistik (D.E.), Georg August Universität Göttingen, Göttingen, Germany; Abteilung Thorax, Herz, Gefäßchirurgie, Herz und Diabeteszentrum Nordrheinwestfalen, Bad Oeynhausen, Germany (A.R., J.G.); Abteilung Herz, Thorax, Gefäßchirurgie und Transplantationschirurgie, Medizinische Hochschule Hannover,
| | - André Renner
- From Abteilung Kardiologie und Pneumologie/Herzzentrum (T.H.F., J.H., S.N., K.T., A.F., G.H., L.S.M., S.S.), Abteilung Thorax, Herz, Gefäßchirurgie/Herzzentrum (T.T., F.A.S.), and Abteilung Medizinische Statistik (D.E.), Georg August Universität Göttingen, Göttingen, Germany; Abteilung Thorax, Herz, Gefäßchirurgie, Herz und Diabeteszentrum Nordrheinwestfalen, Bad Oeynhausen, Germany (A.R., J.G.); Abteilung Herz, Thorax, Gefäßchirurgie und Transplantationschirurgie, Medizinische Hochschule Hannover,
| | - Stefan Neef
- From Abteilung Kardiologie und Pneumologie/Herzzentrum (T.H.F., J.H., S.N., K.T., A.F., G.H., L.S.M., S.S.), Abteilung Thorax, Herz, Gefäßchirurgie/Herzzentrum (T.T., F.A.S.), and Abteilung Medizinische Statistik (D.E.), Georg August Universität Göttingen, Göttingen, Germany; Abteilung Thorax, Herz, Gefäßchirurgie, Herz und Diabeteszentrum Nordrheinwestfalen, Bad Oeynhausen, Germany (A.R., J.G.); Abteilung Herz, Thorax, Gefäßchirurgie und Transplantationschirurgie, Medizinische Hochschule Hannover,
| | - Karl Toischer
- From Abteilung Kardiologie und Pneumologie/Herzzentrum (T.H.F., J.H., S.N., K.T., A.F., G.H., L.S.M., S.S.), Abteilung Thorax, Herz, Gefäßchirurgie/Herzzentrum (T.T., F.A.S.), and Abteilung Medizinische Statistik (D.E.), Georg August Universität Göttingen, Göttingen, Germany; Abteilung Thorax, Herz, Gefäßchirurgie, Herz und Diabeteszentrum Nordrheinwestfalen, Bad Oeynhausen, Germany (A.R., J.G.); Abteilung Herz, Thorax, Gefäßchirurgie und Transplantationschirurgie, Medizinische Hochschule Hannover,
| | - David Ellenberger
- From Abteilung Kardiologie und Pneumologie/Herzzentrum (T.H.F., J.H., S.N., K.T., A.F., G.H., L.S.M., S.S.), Abteilung Thorax, Herz, Gefäßchirurgie/Herzzentrum (T.T., F.A.S.), and Abteilung Medizinische Statistik (D.E.), Georg August Universität Göttingen, Göttingen, Germany; Abteilung Thorax, Herz, Gefäßchirurgie, Herz und Diabeteszentrum Nordrheinwestfalen, Bad Oeynhausen, Germany (A.R., J.G.); Abteilung Herz, Thorax, Gefäßchirurgie und Transplantationschirurgie, Medizinische Hochschule Hannover,
| | - Anna Förster
- From Abteilung Kardiologie und Pneumologie/Herzzentrum (T.H.F., J.H., S.N., K.T., A.F., G.H., L.S.M., S.S.), Abteilung Thorax, Herz, Gefäßchirurgie/Herzzentrum (T.T., F.A.S.), and Abteilung Medizinische Statistik (D.E.), Georg August Universität Göttingen, Göttingen, Germany; Abteilung Thorax, Herz, Gefäßchirurgie, Herz und Diabeteszentrum Nordrheinwestfalen, Bad Oeynhausen, Germany (A.R., J.G.); Abteilung Herz, Thorax, Gefäßchirurgie und Transplantationschirurgie, Medizinische Hochschule Hannover,
| | - Jan D. Schmitto
- From Abteilung Kardiologie und Pneumologie/Herzzentrum (T.H.F., J.H., S.N., K.T., A.F., G.H., L.S.M., S.S.), Abteilung Thorax, Herz, Gefäßchirurgie/Herzzentrum (T.T., F.A.S.), and Abteilung Medizinische Statistik (D.E.), Georg August Universität Göttingen, Göttingen, Germany; Abteilung Thorax, Herz, Gefäßchirurgie, Herz und Diabeteszentrum Nordrheinwestfalen, Bad Oeynhausen, Germany (A.R., J.G.); Abteilung Herz, Thorax, Gefäßchirurgie und Transplantationschirurgie, Medizinische Hochschule Hannover,
| | - Jan Gummert
- From Abteilung Kardiologie und Pneumologie/Herzzentrum (T.H.F., J.H., S.N., K.T., A.F., G.H., L.S.M., S.S.), Abteilung Thorax, Herz, Gefäßchirurgie/Herzzentrum (T.T., F.A.S.), and Abteilung Medizinische Statistik (D.E.), Georg August Universität Göttingen, Göttingen, Germany; Abteilung Thorax, Herz, Gefäßchirurgie, Herz und Diabeteszentrum Nordrheinwestfalen, Bad Oeynhausen, Germany (A.R., J.G.); Abteilung Herz, Thorax, Gefäßchirurgie und Transplantationschirurgie, Medizinische Hochschule Hannover,
| | - Friedrich A. Schöndube
- From Abteilung Kardiologie und Pneumologie/Herzzentrum (T.H.F., J.H., S.N., K.T., A.F., G.H., L.S.M., S.S.), Abteilung Thorax, Herz, Gefäßchirurgie/Herzzentrum (T.T., F.A.S.), and Abteilung Medizinische Statistik (D.E.), Georg August Universität Göttingen, Göttingen, Germany; Abteilung Thorax, Herz, Gefäßchirurgie, Herz und Diabeteszentrum Nordrheinwestfalen, Bad Oeynhausen, Germany (A.R., J.G.); Abteilung Herz, Thorax, Gefäßchirurgie und Transplantationschirurgie, Medizinische Hochschule Hannover,
| | - Gerd Hasenfuss
- From Abteilung Kardiologie und Pneumologie/Herzzentrum (T.H.F., J.H., S.N., K.T., A.F., G.H., L.S.M., S.S.), Abteilung Thorax, Herz, Gefäßchirurgie/Herzzentrum (T.T., F.A.S.), and Abteilung Medizinische Statistik (D.E.), Georg August Universität Göttingen, Göttingen, Germany; Abteilung Thorax, Herz, Gefäßchirurgie, Herz und Diabeteszentrum Nordrheinwestfalen, Bad Oeynhausen, Germany (A.R., J.G.); Abteilung Herz, Thorax, Gefäßchirurgie und Transplantationschirurgie, Medizinische Hochschule Hannover,
| | - Lars S. Maier
- From Abteilung Kardiologie und Pneumologie/Herzzentrum (T.H.F., J.H., S.N., K.T., A.F., G.H., L.S.M., S.S.), Abteilung Thorax, Herz, Gefäßchirurgie/Herzzentrum (T.T., F.A.S.), and Abteilung Medizinische Statistik (D.E.), Georg August Universität Göttingen, Göttingen, Germany; Abteilung Thorax, Herz, Gefäßchirurgie, Herz und Diabeteszentrum Nordrheinwestfalen, Bad Oeynhausen, Germany (A.R., J.G.); Abteilung Herz, Thorax, Gefäßchirurgie und Transplantationschirurgie, Medizinische Hochschule Hannover,
| | - Samuel Sossalla
- From Abteilung Kardiologie und Pneumologie/Herzzentrum (T.H.F., J.H., S.N., K.T., A.F., G.H., L.S.M., S.S.), Abteilung Thorax, Herz, Gefäßchirurgie/Herzzentrum (T.T., F.A.S.), and Abteilung Medizinische Statistik (D.E.), Georg August Universität Göttingen, Göttingen, Germany; Abteilung Thorax, Herz, Gefäßchirurgie, Herz und Diabeteszentrum Nordrheinwestfalen, Bad Oeynhausen, Germany (A.R., J.G.); Abteilung Herz, Thorax, Gefäßchirurgie und Transplantationschirurgie, Medizinische Hochschule Hannover,
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231
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Martin TP, Lawan A, Robinson E, Grieve DJ, Plevin R, Paul A, Currie S. Adult cardiac fibroblast proliferation is modulated by calcium/calmodulin-dependent protein kinase II in normal and hypertrophied hearts. Pflugers Arch 2013; 466:319-30. [DOI: 10.1007/s00424-013-1326-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 06/17/2013] [Accepted: 07/02/2013] [Indexed: 01/10/2023]
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232
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Bai Y, Jones PP, Guo J, Zhong X, Clark RB, Zhou Q, Wang R, Vallmitjana A, Benitez R, Hove-Madsen L, Semeniuk L, Guo A, Song LS, Duff HJ, Chen SRW. Phospholamban knockout breaks arrhythmogenic Ca²⁺ waves and suppresses catecholaminergic polymorphic ventricular tachycardia in mice. Circ Res 2013; 113:517-26. [PMID: 23856523 DOI: 10.1161/circresaha.113.301678] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
RATIONALE Phospholamban (PLN) is an inhibitor of cardiac sarco(endo)plasmic reticulum Ca²⁺ ATPase. PLN knockout (PLN-KO) enhances sarcoplasmic reticulum Ca²⁺ load and Ca²⁺ leak. Conversely, PLN-KO accelerates Ca²⁺ sequestration and aborts arrhythmogenic spontaneous Ca²⁺ waves (SCWs). An important question is whether these seemingly paradoxical effects of PLN-KO exacerbate or protect against Ca²⁺-triggered arrhythmias. OBJECTIVE We investigate the impact of PLN-KO on SCWs, triggered activities, and stress-induced ventricular tachyarrhythmias (VTs) in a mouse model of cardiac ryanodine-receptor (RyR2)-linked catecholaminergic polymorphic VT. METHODS AND RESULTS We generated a PLN-deficient, RyR2-mutant mouse model (PLN-/-/RyR2-R4496C+/-) by crossbreeding PLN-KO mice with catecholaminergic polymorphic VT-associated RyR2-R4496C mutant mice. Ca²⁺ imaging and patch-clamp recording revealed cell-wide propagating SCWs and triggered activities in RyR2-R4496C+/- ventricular myocytes during sarcoplasmic reticulum Ca²⁺ overload. PLN-KO fragmented these cell-wide SCWs into mini-waves and Ca²⁺ sparks and suppressed the triggered activities evoked by sarcoplasmic reticulum Ca²⁺ overload. Importantly, these effects of PLN-KO were reverted by partially inhibiting sarco(endo)plasmic reticulum Ca²⁺ ATPase with 2,5-di-tert-butylhydroquinone. However, Bay K, caffeine, or Li⁺ failed to convert mini-waves to cell-wide SCWs in PLN-/-/RyR2-R4496C+/- ventricular myocytes. Furthermore, ECG analysis showed that PLN-KO mice are not susceptible to stress-induced VTs. On the contrary, PLN-KO protected RyR2-R4496C mutant mice from stress-induced VTs. CONCLUSIONS Our results demonstrate that despite severe sarcoplasmic reticulum Ca²⁺ leak, PLN-KO suppresses triggered activities and stress-induced VTs in a mouse model of catecholaminergic polymorphic VT. These data suggest that breaking up cell-wide propagating SCWs by enhancing Ca²⁺ sequestration represents an effective approach for suppressing Ca²⁺-triggered arrhythmias.
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Affiliation(s)
- Yunlong Bai
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada
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233
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Westenbrink BD, Edwards AG, McCulloch AD, Brown JH. The promise of CaMKII inhibition for heart disease: preventing heart failure and arrhythmias. Expert Opin Ther Targets 2013; 17:889-903. [PMID: 23789646 DOI: 10.1517/14728222.2013.809064] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Calcium-calmodulin-dependent protein kinase II (CaMKII) has emerged as a central mediator of cardiac stress responses which may serve several critical roles in the regulation of cardiac rhythm, cardiac contractility and growth. Sustained and excessive activation of CaMKII during cardiac disease has, however, been linked to arrhythmias, and maladaptive cardiac remodeling, eventually leading to heart failure (HF) and sudden cardiac death. AREAS COVERED In the current review, the authors describe the unique structural and biochemical properties of CaMKII and focus on its physiological effects in cardiomyocytes. Furthermore, they provide evidence for a role of CaMKII in cardiac pathologies, including arrhythmogenesis, myocardial ischemia and HF development. The authors conclude by discussing the potential for CaMKII as a target for inhibition in heart disease. EXPERT OPINION CaMKII provides a promising nodal point for intervention that may allow simultaneous prevention of HF progression and development of arrhythmias. For future studies and drug development there is a strong rationale for the development of more specific CaMKII inhibitors. In addition, an improved understanding of the differential roles of CaMKII subtypes is required.
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Affiliation(s)
- B Daan Westenbrink
- University of California, Department of Pharmacology, San Diego, La Jolla, CA, USA
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234
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Affiliation(s)
- Robert N Correll
- From the Howard Hughes Medical Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
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235
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Visualizing CaMKII and CaM activity: a paradigm of compartmentalized signaling. J Mol Med (Berl) 2013; 91:907-16. [PMID: 23775230 DOI: 10.1007/s00109-013-1060-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 05/16/2013] [Accepted: 05/26/2013] [Indexed: 10/26/2022]
Abstract
Calcium (Ca(2+)) has long been recognized as a crucial intracellular messenger attaining stimuli-specific cellular outcomes via localized signaling. Ca(2+)-binding proteins, such as calmodulin (CaM), and its target proteins are key to the segregation and refinement of these Ca(2+)-dependent signaling events. This review not only summarizes the recent technological advances enabling the study of subcellular Ca(2+)-CaM and Ca(2+)-CaM-dependent protein kinase (CaMKII) signaling events but also highlights the outstanding challenges in the field.
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236
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Sorensen AB, Søndergaard MT, Overgaard MT. Calmodulin in a Heartbeat. FEBS J 2013; 280:5511-32. [DOI: 10.1111/febs.12337] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 04/28/2013] [Accepted: 05/07/2013] [Indexed: 01/16/2023]
Affiliation(s)
- Anders B. Sorensen
- Department of Biotechnology, Chemistry and Environmental Engineering; Aalborg University; Denmark
| | - Mads T. Søndergaard
- Department of Biotechnology, Chemistry and Environmental Engineering; Aalborg University; Denmark
| | - Michael T. Overgaard
- Department of Biotechnology, Chemistry and Environmental Engineering; Aalborg University; Denmark
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237
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Ather S, Respress JL, Li N, Wehrens XHT. Alterations in ryanodine receptors and related proteins in heart failure. Biochim Biophys Acta Mol Basis Dis 2013; 1832:2425-31. [PMID: 23770282 DOI: 10.1016/j.bbadis.2013.06.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 04/23/2013] [Accepted: 06/05/2013] [Indexed: 01/07/2023]
Abstract
Sarcoplasmic reticulum (SR) Ca(2+) release plays an essential role in mediating cardiac myocyte contraction. Depolarization of the plasma membrane results in influx of Ca(2+) through l-type Ca(2+) channels (LTCCs) that in turn triggers efflux of Ca(2+) from the SR through ryanodine receptor type-2 channels (RyR2). This process known as Ca(2+)-induced Ca(2+)release (CICR) occurs within the dyadic region, where the adjacent transverse (T)-tubules and SR membranes allow RyR2 clusters to release SR Ca(2+) following Ca(2+) influx through adjacent LTCCs. SR Ca(2+) released during systole binds to troponin-C and initiates actin-myosin cross-bridging, leading to muscle contraction. During diastole, the cytosolic Ca(2+) concentration is restored by the resequestration of Ca(2+) into the SR by SR/ER Ca(2+)-ATPase (SERCA2a) and by the extrusion of Ca(2+) via the Na(+)/Ca(2+)-exchanger (NCX1). This whole process, entitled excitation-contraction (EC) coupling, is highly coordinated and determines the force of contraction, providing a link between the electrical and mechanical activities of cardiac muscle. In response to heart failure (HF), the heart undergoes maladaptive changes that result in depressed intracellular Ca(2+) cycling and decreased SR Ca(2+) concentrations. As a result, the amplitude of CICR is reduced resulting in less force production during EC coupling. In this review, we discuss the specific proteins that alter the regulation of Ca(2+) during HF. In particular, we will focus on defects in RyR2-mediated SR Ca(2+) release. This article is part of a Special Issue entitled: Heart failure pathogenesis and emerging diagnostic and therapeutic interventions.
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Affiliation(s)
- Sameer Ather
- Dept of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Dept of Medicine (Cardiology), Baylor College of Medicine, Houston, TX, USA
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238
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The effects of neuregulin on cardiac Myosin light chain kinase gene-ablated hearts. PLoS One 2013; 8:e66720. [PMID: 23776695 PMCID: PMC3679076 DOI: 10.1371/journal.pone.0066720] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 05/09/2013] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Activation of ErbB2/4 receptor tyrosine kinases in cardiomyocytes by neuregulin treatment is associated with improvement in cardiac function, supporting its use in human patients with heart failure despite the lack of a specific mechanism. Neuregulin infusion in rodents increases cardiac myosin light chain kinase (cMLCK) expression and cardiac myosin regulatory light chain (RLC) phosphorylation which may improve actin-myosin interactions for contraction. We generated a cMLCK knockout mouse to test the hypothesis that cMLCK is necessary for neuregulin-induced improvement in cardiac function by increasing RLC phosphorylation. PRINCIPAL FINDINGS The cMLCK knockout mice have attenuated RLC phosphorylation and decreased cardiac performance measured as fractional shortening. Neuregulin infusion for seven days in wildtype mice increased cardiac cMLCK protein expression and RLC phosphorylation while increasing Akt phosphorylation and decreasing phospholamban phosphorylation. There was no change in fractional shortening. In contrast, neuregulin infusion in cMLCK knockout animals increased cardiac performance in the absence of cMLCK without increasing RLC phosphorylation. In addition, CaMKII signaling appeared to be enhanced in neuregulin-treated knockout mice. CONCLUSIONS Thus, Neuregulin may improve cardiac performance in the failing heart without increasing cMLCK and RLC phosphorylation by activating other signaling pathways.
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Wenxin-Keli Regulates the Calcium/Calmodulin-Dependent Protein Kinase II Signal Transduction Pathway and Inhibits Cardiac Arrhythmia in Rats with Myocardial Infarction. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:464508. [PMID: 23781262 PMCID: PMC3679760 DOI: 10.1155/2013/464508] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 02/21/2013] [Indexed: 12/19/2022]
Abstract
Wenxin-Keli (WXKL) is a Chinese herbal compound reported to be of benefit in the treatment of cardiac arrhythmia, cardiac inflammation, and heart failure. Amiodarone is a noncompetitive inhibitor of the α- and β-adrenergic receptors and prevents calcium influx in the slow-response cells of the sinoatrial and atrioventricular nodes. Overexpression of Ca2+/calmodulin-dependent protein kinase II (CaMKII) in transgenic mice results in heart failure and arrhythmias. We hypothesised that administration of WXKL and amiodarone can reduce the incidence of arrhythmias by regulating CaMKII signal transduction. A total of 100 healthy Sprague Dawley rats were used in the study. The rats were randomly divided into four groups (a sham group, a myocardial infarction (MI) group, a WXKL-treated group, and an amiodarone-treated group). A myocardial infarction model was established in these rats by ligating the left anterior descending coronary artery for 4 weeks. Western blotting was used to assess CaMKII, p-CaMKII (Thr-286), PLB, p-PLB (Thr-17), RYR2, and FK binding protein 12.6 (FKBP12.6) levels. The Ca2+ content in the sarcoplasmic reticulum (SR) and the calcium transient amplitude were studied by confocal imaging using the fluorescent indicator Fura-4. In conclusion, WXKL may inhibit heart failure and cardiac arrhythmias by regulating the CaMKII signal transduction pathway similar to amiodarone.
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Fischer TH, Neef S, Maier LS. The Ca-calmodulin dependent kinase II: A promising target for future antiarrhythmic therapies? J Mol Cell Cardiol 2013; 58:182-7. [DOI: 10.1016/j.yjmcc.2012.11.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 11/02/2012] [Accepted: 11/05/2012] [Indexed: 12/19/2022]
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While systolic cardiomyocyte function is preserved, diastolic myocyte function and recovery from acidosis are impaired in CaMKIIδ-KO mice. J Mol Cell Cardiol 2013; 59:107-16. [PMID: 23473775 DOI: 10.1016/j.yjmcc.2013.02.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 02/18/2013] [Indexed: 12/14/2022]
Abstract
OBJECTIVE CaMKII contributes to impaired contractility in heart failure by inducing SR Ca(2+)-leak. CaMKII-inhibition in the heart was suggested to be a novel therapeutic principle. Different CaMKII isoforms exist. Specifically targeting CaMKIIδ, the dominant isoform in the heart, could be of therapeutic potential without impairing other CaMKII isoforms. RATIONALE We investigated whether cardiomyocyte function is affected by isoform-specific knockout (KO) of CaMKIIδ under basal conditions and upon stress, i.e. upon ß-adrenergic stimulation and during acidosis. RESULTS Systolic cardiac function was largely preserved in the KO in vivo (echocardiography) corresponding to unchanged Ca(2+)-transient amplitudes and isolated myocyte contractility in vitro. CaMKII activity was dramatically reduced while phosphatase-1 inhibitor-1 was significantly increased. Surprisingly, while diastolic Ca(2+)-elimination was slower in KO most likely due to decreased phospholamban Thr-17 phosphorylation, frequency-dependent acceleration of relaxation was still present. Despite decreased SR Ca(2+)-reuptake at lower frequencies, SR Ca(2+)-content was not diminished, which might be due to reduced diastolic SR Ca(2+)-loss in the KO as a consequence of lower RyR Ser-2815 phosphorylation. Challenging KO myocytes with isoproterenol showed intact inotropic and lusitropic responses. During acidosis, SR Ca(2+)-reuptake and SR Ca(2+)-loading were significantly impaired in KO, resulting in an inability to maintain systolic Ca(2+)-transients during acidosis and impaired recovery. CONCLUSIONS Inhibition of CaMKIIδ appears to be safe under basal physiologic conditions. Specific conditions exist (e.g. during acidosis) under which CaMKII-inhibition might not be helpful or even detrimental. These conditions will have to be more clearly defined before CaMKII inhibition is used therapeutically.
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Zhang H, Gomez AM, Wang X, Yan Y, Zheng M, Cheng H. ROS regulation of microdomain Ca(2+) signalling at the dyads. Cardiovasc Res 2013; 98:248-58. [PMID: 23455546 DOI: 10.1093/cvr/cvt050] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Reactive oxygen species (ROS) are emerging as centre-stage players in cardiac functional regulation. ROS and Ca(2+) signals converge at dyads, the structural and functional units of cardiac excitation-contraction coupling. These two prominent signalling systems are intertwined with ROS modulation of the entire Ca(2+)-signalling network, and vice versa. While constitutively generated homoeostatic ROS are important in setting the redox potential of the intracellular milieu, dynamic signalling ROS shape microdomain and global Ca(2+) signals on both the beat-to-beat and greater time scales. However, ROS effects are complex and subtle, characterized by multiphasic and bidirectional Ca(2+) responses; and sustained oxidative stress may lead to compromised contractility and arrhythmogenicity. These new understandings should be leveraged to harness ROS for their beneficial roles while avoiding deleterious effects in the heart.
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Affiliation(s)
- Huiliang Zhang
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing 100871, China
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243
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Electrical storm: recent pathophysiological insights and therapeutic consequences. Basic Res Cardiol 2013; 108:336. [DOI: 10.1007/s00395-013-0336-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 01/29/2013] [Accepted: 02/04/2013] [Indexed: 01/01/2023]
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244
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Shaw RM, Colecraft HM. L-type calcium channel targeting and local signalling in cardiac myocytes. Cardiovasc Res 2013; 98:177-86. [PMID: 23417040 DOI: 10.1093/cvr/cvt021] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
In the heart, Ca(2+) influx via Ca(V)1.2 L-type calcium channels (LTCCs) is a multi-functional signal that triggers muscle contraction, controls action potential duration, and regulates gene expression. The use of LTCC Ca(2+) as a multi-dimensional signalling molecule in the heart is complicated by several aspects of cardiac physiology. Cytosolic Ca(2+) continuously cycles between ~100 nM and ~1 μM with each heartbeat due to Ca(2+) linked signalling from LTCCs to ryanodine receptors. This rapid cycling raises the question as to how cardiac myocytes distinguish the Ca(2+) fluxes originating through L-type channels that are dedicated to contraction from Ca(2+) fluxes originating from other L-type channels that are used for non-contraction-related signalling. In general, disparate Ca(2+) sources in cardiac myocytes such as current through differently localized LTCCs as well as from IP3 receptors can signal selectively to Ca(2+)-dependent effectors in local microdomains that can be impervious to the cytoplasmic Ca(2+) transients that drive contraction. A particular challenge for diversified signalling via cardiac LTCCs is that they are voltage-gated and, therefore, open and presumably flood their microdomains with Ca(2+) with each action potential. Thus spatial localization of Cav1.2 channels to different types of microdomains of the ventricular cardiomyocyte membrane as well as the existence of particular macromolecular complexes in each Cav1.2 microdomain are important to effect different types of Cav1.2 signalling. In this review we examine aspects of Cav1.2 structure, targeting and signalling in two specialized membrane microdomains--transverse tubules and caveolae.
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Affiliation(s)
- Robin M Shaw
- Cardiovascular Research Institute and Department of Medicine, University of California, San Francisco, CA 94143, USA
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245
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Belevych AE, Radwański PB, Carnes CA, Györke S. 'Ryanopathy': causes and manifestations of RyR2 dysfunction in heart failure. Cardiovasc Res 2013; 98:240-7. [PMID: 23408344 DOI: 10.1093/cvr/cvt024] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The cardiac ryanodine receptor (RyR2), a Ca(2+) release channel on the membrane of the sarcoplasmic reticulum (SR), plays a key role in determining the strength of the heartbeat by supplying Ca(2+) required for contractile activation. Abnormal RyR2 function is recognized as an important part of the pathophysiology of heart failure (HF). While in the normal heart, the balance between the cytosolic and intra-SR Ca(2+) regulation of RyR2 function maintains the contraction-relaxation cycle, in HF, this behaviour is compromised by excessive post-translational modifications of the RyR2. Such modification of the Ca(2+) release channel impairs the ability of the RyR2 to properly deactivate leading to a spectrum of Ca(2+)-dependent pathologies that include cardiac systolic and diastolic dysfunction, arrhythmias, and structural remodelling. In this article, we present an overview of recent advances in our understanding of the underlying causes and pathological consequences of abnormal RyR2 function in the failing heart. We also discuss the implications of these findings for HF therapy.
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Affiliation(s)
- Andriy E Belevych
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
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246
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Hamdani N, Krysiak J, Kreusser MM, Neef S, Dos Remedios CG, Maier LS, Krüger M, Backs J, Linke WA. Crucial role for Ca2(+)/calmodulin-dependent protein kinase-II in regulating diastolic stress of normal and failing hearts via titin phosphorylation. Circ Res 2013; 112:664-74. [PMID: 23283722 DOI: 10.1161/circresaha.111.300105] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
RATIONALE Myocardial diastolic stiffness and cardiomyocyte passive force (F(passive)) depend in part on titin isoform composition and phosphorylation. Ca(2+)/calmodulin-dependent protein kinase-II (CaMKII) phosphorylates ion channels, Ca(2+)-handling proteins, and chromatin-modifying enzymes in the heart, but has not been known to target titin. OBJECTIVE To elucidate whether CaMKII phosphorylates titin and modulates F(passive) in normal and failing myocardium. METHODS AND RESULTS Titin phosphorylation was assessed in CaMKIIδ/γ double-knockout (DKO) mouse, transgenic CaMKIIδC-overexpressing mouse, and human hearts, by Pro-Q-Diamond/Sypro-Ruby staining, autoradiography, and immunoblotting using phosphoserine-specific titin-antibodies. CaMKII-dependent site-specific titin phosphorylation was quantified in vivo by mass spectrometry using stable isotope labeling by amino acids in cell culture mouse heart mixed with wild-type (WT) or DKO heart. F(passive) of single permeabilized cardiomyocytes was recorded before and after CaMKII-administration. All-titin phosphorylation was reduced by >50% in DKO but increased by up to ≈100% in transgenic versus WT hearts. Conserved CaMKII-dependent phosphosites were identified within the PEVK-domain of titin by quantitative mass spectrometry and confirmed in recombinant human PEVK-fragments. CaMKII also phosphorylated the cardiac titin N2B-unique sequence. Phosphorylation at specific PEVK/titin N2B-unique sequence sites was decreased in DKO and amplified in transgenic versus WT hearts. F(passive) was elevated in DKO and reduced in transgenic compared with WT cardiomyocytes. CaMKII-administration lowered F(passive) of WT and DKO cardiomyocytes, an effect blunted by titin antibody pretreatment. Human end-stage failing hearts revealed higher CaMKII expression/activity and phosphorylation at PEVK/titin N2B-unique sequence sites than nonfailing donor hearts. CONCLUSIONS CaMKII phosphorylates the titin springs at conserved serines/threonines, thereby lowering F(passive). Deranged CaMKII-dependent titin phosphorylation occurs in heart failure and contributes to altered diastolic stress.
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Affiliation(s)
- Nazha Hamdani
- Department of Cardiovascular Physiology, Ruhr University Bochum, Bochum, Germany
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247
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Rokita AG, Anderson ME. New therapeutic targets in cardiology: arrhythmias and Ca2+/calmodulin-dependent kinase II (CaMKII). Circulation 2013; 126:2125-39. [PMID: 23091085 DOI: 10.1161/circulationaha.112.124990] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Adam G Rokita
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
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248
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van Berlo JH, Maillet M, Molkentin JD. Signaling effectors underlying pathologic growth and remodeling of the heart. J Clin Invest 2013; 123:37-45. [PMID: 23281408 DOI: 10.1172/jci62839] [Citation(s) in RCA: 334] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Cardiovascular disease is the number one cause of mortality in the Western world. The heart responds to many cardiopathological conditions with hypertrophic growth by enlarging individual myocytes to augment cardiac pump function and decrease ventricular wall tension. Initially, such cardiac hypertrophic growth is often compensatory, but as time progresses these changes become maladaptive. Cardiac hypertrophy is the strongest predictor for the development of heart failure, arrhythmia, and sudden death. Here we discuss therapeutic avenues emerging from molecular and genetic studies of cardiovascular disease in animal models. The majority of these are based on intracellular signaling pathways considered central to pathologic cardiac remodeling and hypertrophy, which then leads to heart failure. We focus our discussion on selected therapeutic targets that have more recently emerged and have a tangible translational potential given the available pharmacologic agents that could be readily evaluated in human clinical trials.
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Affiliation(s)
- Jop H van Berlo
- Department of Pediatrics, University of Cincinnati, Cincinnati Children’s Hospital Medical Center, Howard Hughes Medical Institute, Cincinnati, Ohio 45229-3039, USA
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Menick DR, Li MS, Chernysh O, Renaud L, Kimbrough D, Kasiganesan H, Mani SK. Transcriptional pathways and potential therapeutic targets in the regulation of Ncx1 expression in cardiac hypertrophy and failure. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 961:125-35. [PMID: 23224875 PMCID: PMC3624972 DOI: 10.1007/978-1-4614-4756-6_11] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Changes in cardiac gene expression contribute to the progression of heart failure by affecting cardiomyocyte growth, function, and survival. The Na(+)-Ca(2+) exchanger gene (Ncx1) is upregulated in hypertrophy and is often found elevated in end-stage heart failure. Studies have shown that the change in its expression contributes to contractile dysfunction. Several transcriptional pathways mediate Ncx1 expression in pathological cardiac remodeling. Both α-adrenergic receptor (α-AR) and β-adrenergic receptor (β-AR) signaling can play a role in the regulation of calcium homeostasis in the cardiomyocyte, but chronic activation in periods of cardiac stress contributes to heart failure by mechanisms which include Ncx1 upregulation. Our studies have even demonstrated that NCX1 can directly act as a regulator of "activity-dependent signal transduction" mediating changes in its own expression. Finally, we present evidence that histone deacetylases (HDACs) and histone acetyltransferases (HATs) act as master regulators of Ncx1 expression. We show that many of the transcription factors regulating Ncx1 expression are important in cardiac development and also in the regulation of many other genes in the so-called fetal gene program, which are activated by pathological stimuli. Importantly, studies have revealed that the transcriptional network regulating Ncx1 expression is also mediating many of the other changes in genetic remodeling contributing to the development of cardiac dysfunction and revealed potential therapeutic targets for the treatment of hypertrophy and failure.
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Screening for novel calcium-binding proteins that regulate cardiac hypertrophy: CIB1 as an example. Methods Mol Biol 2013; 963:279-301. [PMID: 23296617 DOI: 10.1007/978-1-62703-230-8_17] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Calcium-binding proteins have a crucial function in the regulation of cardiac contractility as well as in the regulation of cardiac signal-transduction. Because they sense calcium concentrations and at the same time bind specific signaling molecules, some of these proteins are critically involved in the establishment of signaling microdomains, which are insulated from the large cytosolic calcium fluctuations involved in cardiac excitation-contraction coupling. In this regard, we have recently identified the calcium-binding protein CIB1 as an important regulator of pathological cardiac hypertrophy and transition to heart failure. It is almost certain that more, currently unknown calcium-binding proteins with similar regulatory function in cardiac signaling exist. Here, I suggest screening strategies to identify these calcium-binding proteins with impact on cardiac hypertrophy and provide a detailed protocol for the identification of protein interaction partners. I also describe cell culture-based models for cardiomyocyte hypertrophy as well as mouse models for pathological or physiological hypertrophy and strategies to analyze the impact of candidate genes on the development of hypertrophy.
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