Mitochondria and the Heart

Mitochondria and the Heart

Developments in Cardiovascular Medicine

232. A. Bayes de Luna, F. Furlanello, B J . Maron and D.P. Zipes (eds.):

Arrhythmias and Sudden Death in Athletes. 2000 ISBN: 0-7923-6337-X 233. J-C. Tardif and M.G. Bourassa (eds): Antioxidants and Cardiovascular Disease.

2000. ISBN: 0-7923-7829-6 234. J. Candell-Riera, J. Castell-Conesa, S. Aguade Bruiz (eds): Myocardium at

Risk and Viable Myocardium Evaluation by SPET. 2000.ISBN: 0-7923-6724-3 235. M.H. Ellestad and E. Amsterdam (eds): Exercise Testing: New Concepts for the

New Century. 2001. ISBN: 0-7923-7378-2 236. Douglas L. Mann (ed.): The Role of Inflammatory Mediators in the Failing

Heart. 2001 ISBN: 0-7923-7381-2 237. Donald M. Bers (ed.): Excitation-Contraction Coupling and Cardiac

Contractile Force, Second Edition. 2001 ISBN: 0-7923-7157-7 238. Brian D. Hoit, Richard A. Walsh (eds.): Cardiovascular Physiology in the

Genetically Engineered Mouse, Second Edition. 2001 ISBN 0-7923-7536-X 239. Pieter A. Doevendans, A.A.M. Wilde (eds.): Cardiovascular Genetics for Clinicians

2001 ISBN 1-4020-0097-9 240. Stephen M. Factor, Maria A.Lamberti-Abadi, Jacobo Abadi (eds.): Handbook of

Pathology and Pathophysiology of Cardiovascular Disease. 2001

ISBN 0-7923-7542-4 241. Liong Bing Liem, Eugene Downar (eds): Progress in Catheter Ablation. 2001

ISBN 1-4020-0147-9 242. Pieter A. Doevendans, Stefan Kaab (eds): Cardiovascular Genomics: New

Pathophysiological Concepts. 2002 ISBN 1-4020-7022-5 243. Daan Kromhout, Alessandro Menotti, Henry Blackburn (eds.): Prevention

of Coronary Heart Disease: Diet, Lifestyle and Risk Factors in the Seven

Countries Study. 2002 ISBN 1 -4020-7123-X 244. Antonio Pacifico (ed.), Philip D. Henry, Gust H. Bardy, Martin Borggrefe,

Francis E. Marchlinski, Andrea Natale, Bruce L. Wilkoff (assoc. eds):

Implantable Defibrillator Therapy: A Clinical Guide. 2002 ISBN 1-4020-7143-4 245. Hein J.J. Wellens, Anton P.M. Gorgels, Pieter A. Doevendans (eds.):

The ECG in Acute Myocardial Infarction and Unstable Angina: Diagnosis and Risk Stratification. 2002 ISBN 1-4020-7214-7 246. Jack Rychik, Gil Wernovsky (eds.): Hypoplastic Left Heart Syndrome. 2003

ISBN 1-4020-7319-4 247. Thomas H. Marwick: Stress Echocardiography. Its Role in the Diagnosis and Evaluation

of Coronary Artery Disease 2nd Edition. ISBN 1 -4020-7369-0 248. Akira Matsumori: Cardiomyopathies and Heart Failure: Biomolecular, Infectious

and Immune Mechanisms. 2003 ISBN 1-4020-7438-7 249. Ralph Shabetai: The Pericardium. 2003 ISBN 1-4020-7639-8 250. Irene D. Turpie; George A. Heckman (eds.): Aging Issues in Cardiology. 2004

ISBN 1-40207674-6 251. C.H. Peels; L.H.B. Baur (eds.): Valve Surgery at the Turn of the Millennium. 2004

ISBN 1-4020-7834-X 252. Jason X.-J. Yuan (ed.): Hypoxic Pulmonary Vasoconstriction: Cellular and Molecular

Mechanisms. 2004 ISBN 1-4020-7857-9 253. Francisco J. Villarreal (ed.): Interstitial Fibrosis In Heart Failure 2004

ISBN 0-387-22824-1 254. Xander H.T. Wehrens; Andrew R. Marks (eds.): Ryanodine Receptors: Structure, function

and dysfunction in clinical disease. 2005 ISBN 0-387-23187-0 255. Guillem Pons-Llado; Francesc Carreras (eds.): Atlas of Practical Applications of

Cardiovascular Magnetic Resonance. 2005 ISBN 0-387-23632-5 256. Jose Marin-Garcia : Mitochondria and the Heart. 2005 ISBN 0-387-25574-5 Previous volumes are still available

Mitochondria and the Heart

Edited by

Jose Marin-Garcia

The Molecular Cardiology and Neuromuscular Institute, Highland Park, New Jersey

Department of Physiology & Biophysics, UMDNJ-Robert Wood Johnson Medical School Piscataway, New Jersey

With the collaboration of

Michael J Goldenthal

The Molecular Cardiology Institute, Highland Park, New Jersey

4jj Springer

JosÈ MarÌn-GarcÌa

The Molecular Cardiology and Neuromuscular Institute Highland Park, New Jersey

Department of Physiology & Biophysics UMDNJ-Robert Wood Johnson Medical School Piscataway, New Jersey

Library of Congress Cataloging-in-Publication Data A C.I.P. Catalogue record for this book is available from the Library of Congress.

ISBN-10 0-387-25574-5 e-ISBN 0-387-25575-3 ISBN-13 978-0387-25574-3 e-ISBN 978-0387-25575-0 Printed on acid-free paper.

© 2005 Springer Science+Business Media, Inc.

All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, Inc., 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now know or hereafter developed is forbidden.

The use in this publication of trade names, trademarks, service marks and similar terms, even if the are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights.

While the advice and information in this book are believed to be true and accurate at the date of going to press, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein.

Printed in the United States of America.

9 8 7 6 5 4 3 2 1 SPIN 11055679 springeronline.com

Dedication

This book is dedicated to my

wife, Daniele, and daughter,

Melanie, with love

Contents

1. An Introduction to Mitochondria and the Heart

Overview 1

What are mitochondria? 1

How to study mitochondria: New and old 3 Mitochondrial bioenergetics 6

Mitochondrial biogenesis 7

Cardiac mitochondrial changes during cardiac growth and development 9

Mitochondria: the primary site of ROS generation and also a critical target of its damaging effects 10

Mitochondrial dysfunction in cardiovascular disease 10

Defects in mtDNA 10

Defects in nuclear-DNA encoded mitochondrial proteins 12

Myocardial ischemia and ETC 13 Apoptosis and cell death 14

Animal models of mitochondrial-associated cardiovascular disease 15

Diagnosis and treatment of mitochondrial-based cardiac diseases 16

The road ahead 16

References 17

viii Mitochondria and the Heart

2. Mitochondrial Bioenergetics in the Heart 27

Overview 27 Introduction 27

Complex I (NADH-ubiquinone oxidoreductase) 28 Enzyme structure 29

Complex II (Succinate-ubiquinone oxidoreductase) 30 Complex III (Ubiquinol-cytochrome c oxidoreductase) 32 The Q cycle and bcl function 33

Complex IV (Cytochrome c oxidase) 35 COX enzyme structure 36

COX subunit gene structure and expression 37 COX activity regulation 39

Complex V (F

-Fi ATPase; ATP synthase) 40 Subunit composition, structure, and function 40 ATP synthase defects and related pathologies 44 Other enzymes bioenergetics 45

Adenine nucleotide translocator (ANT) 45 ANT structure 47

ANT regulation in the heart 47 ANT genes and their expression 47 ANT dysfunction plays a key role in

cardiac pathology 48 Creatine kinase 49 Structure 50

Creatine kinase and the heart 51 PDH and the TCA (Krebs) cycle 52

Overall regulation of mitochondrial bioenergetic in the heart 53

Supply and demand, substrates, and oxygen and ATP-ADP levels 53

References 56

CONTENTS ix

3, Heart Mitochondrial Biogenesis 63

Overview 63 Introduction 63

Structure of mtDNA 64 MtDNA Function 66 Replication 66

Regulation of mtDNA replication 69

Mitochondrial transcription and RNA processing 70 Regulation of mitochondrial transcription and

processing 72

Mitochondrial translation 73 Mitochondrial ribosomes 73

Initiation and elongation of translation 76 Mitochondria DNA repair 76

Nuclear participation in mitochondrial biogenesis 79 Nuclear regulatory proteins and coordination

of transcriptional events 79

Hormones affecting both mitochondrial and nuclear transcription 82

Mitochondria import and assembly of proteins 83 Relevance of mitochondrial biogenesis 85

References 85

4. ROS Generation, Antioxidants,

and Cell Death 99

Overview 99 Introduction 99

The significance of ROS 100 Generation of ROS 100 Negative effect of ROS 102 Antioxidant defense 104

Role of ROS in cell signaling 106 ROS and cardiac pathology 106 ROS and apoptosis 108

Apoptosis and cell death 109

Myocardial apoptosis 112

References 113

Mitochondria and the Heart

5. Myocardial Ischemia and

Cardioprotection 123

Overview 123 Introduction 123

Mitochondrial dysfunction in myocardial ischemia 124 Oxidation-phosphorylation decline in ischemia 124 Myocardial ischemia and oxidative stress 126 Myocardial ischemia and mitochondrial

calcium flux 127 Gene expression 128 Reperfusion 129 Cardioprotection 129

Ischemic cardioprotection 129

Cascade of mitochondrial events in IPC 131 Signaling pathways 134

Adenosine and other ligands 134

Activation and translocation of PKC as a pivotal signaling event in the genesis of IPC and CP 136

Reactive oxygen species 137

Cardioprotection: An emerging field 138 Early and late IPC pathways 139

Potential applications to clinical medicine 142 References 143

6. Mitochondria Dysfunction in

Cardiomyopathy and Heart failure 157

Overview 157 Introduction 157

Mitochondria are the major source of bioenergy in the cardiac cell 158

What is the evidence for myocardial dependency on mitochondrial function? 160

Mitochondrial dysfunction and cardiomyopathy:

Support from human studies 160

CONTENTS xi

Clinical evidence of nuclear mutations in mitochondrial components 165

Constribution of transgenic models to the study of mitochondria in heart dysfunction 166

Evidence from animals models that mitochondrial bioenergetic enzymes play a critical role in HF 168 Mitochondrial dysfunction and other cellular pathways

in cardiomyopathy 169

Mutations in contractile/sarcomere proteins and mitochondrial function 170

Mitochondrial function and cardiac hypertrophy 173 Calcium signaling and mitochondrial function in HF 174 Mitochondrial function and apoptosis in HF 174

What events occurring in HF are truly tissue-specific? 176 Future prospects 178

References 179

1. Fatty Acid and Glucose Metabolism in

Cardiac Disease 197

Overview 197 Introduction 197

Role of fatty acids and their metabolism in the normal cardiomyocyte: Structural and regulatory roles in cardiac cell membranes 198

Fatty acid transporters and glucose carriers 198 B ioenergetics of FAO 201

Cellular location of FAO and glucose oxidation 204

The effect of disorders of fatty acid and glucose metabolism on cardiac structure/function 205

Secondary effects on mitochondrial fatty acid (3-oxidation:

Relationship to mitochondrial respiration and OXPHOS 208 Fatty acid metabolism defects and their association with

cardiomyopathy and arrhythmias 208 Cardiomyopathy 208

Arrhythmias and conduction defects 209

xii Mitochondria and the Heart

Fatty acids, glucose, and cardiac apoptosis 210

Abnormalities in mtDNA and their association with both diabetes and cardiomyopathy 211

Molecular players in fatty acid-related cardiac diseases;

modulation of gene expression 211 MCAD 211

VLCAD 212 CPT-II 212 MTP 212 PPAR 213

Peroxisome proliferator-activated receptor y coactivator (PGC- l a ) 215

Animal models of defective fatty acid metabolism and cardiac failure 216

Advances in diagnostics and treatment of fatty acid/cardiac disease 217

References 218

8. Mitochondria in Pediatric Cardiology 229

Overview 229

MlTOCHONDRIAL CARDIOMYOPATHY 229

Introduction 229 Diagnosis 232 Clinical signs 233

Histological and electron microscopic (EM) analysis 233 Biochemical analysis 235

MtDNA analysis 236

Mitochondrial tRNA mutations 236

Mitochondrial structural gene mutations 241 ATP synthase (ATPase6) 241

Cytochrome b (cytb) 242

Mutations in COX and ND subunits 243 MtDNA depletion 244

MITOCHONDRIA AND CONGENITAL HEART DEFECTS (CHD) 245

Structural and functional cardiac defects 245

Cardiac arrhythmias 246

CONTENTS xiii

Other congenital cardiomyopathies with mitochondrial defects 246

Congenital heart defects and mitochondrial respiration 247 Conclusions 248

References 249

9. Mitochondria and the Aging Heart 263

Overview 263 Introduction 264

Bioenergetics and gene expression in the aging heart 265 Mitochondrial function and gene expression in the

aging heart 266

ROS in the aging heart 268

Mitochondrial DNA damage in the aging heart 270 Rat model of cardiac aging: Defects in ETC 273 Gene expression 275

DNA copy number and damage analysis 275 Comments 276

On mitochondrial dysfunction 276 On mitochondrial DNA damage 277

On gene expression of mitochondrial stress proteins and cellular programming 277

On mitochondrial PT pore 278 Conclusions 278

Potential approaches to reverse mitochondrial dysfunction in the aging heart 279

References 281

10. Heart Mitochondria Signaling

Pathways 289

Overview 289 Introduction 289

Mitochondrial abnormalities, signaling defects, and

myocardial disease 290

xiv Mitochondria and the Heart

Mitochondrial signaling in myocardial ischemia and cardioprotection 291

Mitochondrial signaling and myocardial hypertrophy 294

Signaling the mitochondria: Key players 296 Nuclear gene activation 296

Protein kinases 298 Calcium signaling 300 Mitochondrial receptors 301

Signals of survival and stress impact heart mitochondria 302

Survival signals and apoptosis 304 Stress signals 306

Metabolic signals 307

Future prospects: Therapeutic targets and directions 307 The essential role played by mitochondriain in cytoprotective

signaling and CP 307

Mitochondrial metabolic intermediates 308 Summary 309

References 310

11. Treatment of Mitochondrial-Based Cardiac Diseases: Targeting the

Organelle 323

Overview 323 Introduction 323

Treatment of respiratory and metabolic defects 324 Use of antioxidants 325

Treatment of FAO disorders, arrhythmias, and CHF 327 Cardioprotective agents 329

New approaches in treatment 333

Gene therapy in cardiovascular diseases 333 Mitochondria and gene therapy 336

Targeting mitochondria using nucleic acids 336

Targeting mitochondria using bioactive compounds 339

References 340

CONTENTS xv

12. Future Frontiers in Mitochondrial

Cardiac Biology 351

Overview 351 Introduction 351

Disease gene identification: Diagnostic application 353 Modifying factors, Epigenetics, and SNPs 354

Animal models of mitochondrial-based heart disease 360

Cellular engineering 363

Applications of stem cells in mitochondrial defects and toxicology 365

References 367

Glossary 377

Index 388

Preface

Mitochondria have been pivotal in the development of some of the most important ideas in modern biology. Since the discovery that the organelle has its own DNA and specific mutations were found in association with neuromuscular and cardiovascular diseases and with aging, an extraordi-nary number of publications have followed, and the term mitochondrial medicine was coined. Furthermore, our understanding of the multiple roles that mitochondria play in cardiac cell homeostasis opened the door for intensive experimentation to understand the pathogenesis and to find new treatments for cardiovascular diseases.

Besides its role in adenosine triphosphate generation, mitochondria regu-late a complex network of cellular interactions, involving (1) generation and detoxification of reactive oxygen species, including superoxide anion, hy-drogen peroxide, and hydroxyl radical; (2) maintenance of the antioxidant glutathione in a reduced state and adequate level of mitochondrial matrix superoxide dismutase; (3) cytoplasmic calcium homeostasis, particularly under conditions of cellular calcium loading; (4) transport of metabolites between cytoplasm and matrix; (5) both programmed (apoptosis) and necrotic cell death; and (6) cell growth and development. It is therefore not surprising that this organelle has come to be the center stage in many current investigations of cardiovascular diseases, aging, and aging- related disease. Concomitant with these advances, an impressive effort is under- way for the development of new tools and methodologies to study mitochondrial structure and function, including powerful ways to visualize, monitor, and alter the organelle function to assess the genetic consequences of these perturbations.

Because the heart is highly dependent for its function on oxidative energy that is generated in mitochondria—primarily by fatty acid p- oxidation, respiratory electron chain, and oxidative phosphorylation (OXPHOS)—it is understandable that defects in mitochondrial structure and function can be found in association with cardiovascular diseases.

Abnormalities in the organelle structure and function are being

increas-ingly reported in association with conditions such as dilated and

hypertro-phic cardiomyopathy, cardiac conduction defects and sudden

xviii Mitochondria and the Heart death, ischemic and alcoholic cardiomyopathy, myocarditis, and neuromuscular diseases associated with cardiac disease and aging.

Some of the mitochondrial abnormalities may have a genetic basis (e.g., mitochondrial DNA changes might lead to abnormal OXPHOS, and fatty acid oxidation defects might be due to specific nuclear DNA mutations), while other abnormalities may be due to a more sporadic or environmental cardiotoxic insult or may not yet be characterized.

To understand the role that mitochondria play in cardiovascular disease, we discuss the biogenesis and function of cardiac mitochondria during normal growth, development, and aging. Within this context, we then examine the interaction and characterization of mitochondria and mitochondrial abnormalities in cardiac diseases, their diagnosis, therapeutic options currently available, future directions for research, and new frontiers in treatment. While aberrations in the bioenergetic function of the mitochondria are frequently related to cardiac dysfunction, the specific defect causing the bioenergetic abnormalities often resides in a nonbioenergetic pathway (e.g., signaling between the mitochondria and nucleus) or in the overall mitochondrial biogenesis or degradation pathways. Understanding these pathways and the effects that mitochondrial defects have in cardiac pathology is extremely important in establishing the diagnosis and treatment of mitochondrial- based cardiac diseases.

As mitochondria's role in the field of cardiology is strengthened and as research on the multiple functions of this organelle continues its expansion, the time seems appropriate for a book that may integrate known facts, what is developing and what will be known in the near future. In addition to providing a recount of past discoveries, the book deals with areas that are of emerging interest to researchers and clinicians, eyeing potential alternatives that may improve currently available therapies and interventions in the management of cardiovascular diseases in general and the cardiovascular pathology of aging in particular.

It is hoped that this work will further advance the field of mitochondrial medicine.

"New discoveries, fragments of the past, parts of the future."

Jose Marin-Garcia

Highland Park, New Jersey