Healing heart attack victims, one cell at a time

April 03, 2009

LIVERMORE, Calif. -- By using the amount of carbon 14 in the atmosphere from above-ground nuclear testing in the 1950s and 1960, researchers have determined that cells in the human heart develop into adulthood.

But as humans age, the percentage of new heart cells decreases markedly. By age 25, renewal of heart cells gradually decrease from 1 percent turning over annually to .45 percent by the age of 75. About 50 percent of the heart cells a human is born with will regenerate during a lifetime.

Myocardial damage often results in chronic heart failure because of the loss and insufficient regeneration of heart cells. But this new finding may mean that patients, who have suffered myocardial damage as a result of a heart attack, may have some good news.

Lawrence Livermore National Laboratory scientist Bruce Buchholz with colleagues from the Karolinska Institute, Université Claude Bernard Lyon, Lund University and Lund University Hospital, found that cells in a human heart can develop into adulthood and the age of heart cells is, on average, six years younger than the individual.

Using the Laboratory's Center for Accelerator Mass Spectrometry, Buchholz measured the amount of carbon 14 in DNA to establish the age of caridiomyocytes (cardiac muscle cells) in humans.

Carbon 14 atmospheric concentration levels remained relatively stable until the Cold War, when above-ground nuclear bomb tests caused a sharp increase, or peak, which decreased slowly after the end of above-ground testing in 1963. This spike in carbon 14 in the atmosphere serves as a chronometer of the past 55 years.

Because DNA is stable after a cell has gone through its last cell division, the concentration of carbon 14 in DNA serves as a date mark for when a cell was born and can be used to date cells in humans.

The team determined the ages of heart cells by determining the time at which the sample's carbon 14 concentration corresponded to the atmospheric concentration. Buchholz found that people born around or after the nuclear bomb tests corresponded to atmospheric concentrations several years after the subjects' birth, indicating substantial postnatal DNA syntheses.

"By analyzing individuals born at different times before 1955, it is possible to establish the age up to which DNA synthesis occurs, or whether it continues beyond that age," Buchholz said.

In the study, carbon 14 concentrations were elevated in subjects compared to those people born up to 22 years before the beginning of nuclear bomb tests.

"DNA of myocardial cells is synthesized many years after birth, indicating that cells in the human heart do, in fact, renew into adulthood," Buchholz said. "At the age of 50, 55 percent of the heart's cells remain from the time around birth and 45 percent have been generated later."

Cardiac muscles have a striated appearance and their contraction in the heart propels blood from the atria and ventricles to the blood vessels of the circulatory system.

The limited recovery in humans after a heart injury, such as a heart attack, demonstrates failing regeneration of heart cells. But the team concluded that the renewal of heart cells, as indicated by the mixing of carbon 14 in the DNA, suggest that the development of pharmacological strategies to stimulate this process may be a rational alternative or complement to cell transplantation strategies for heart cell replacement.

The research appears in the April 3 edition of the journal Science.

Founded in 1952, Lawrence Livermore National Laboratory is a national security laboratory, with a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by Lawrence Livermore National Security, LLC for the U.S. Department of Energy's National Nuclear Security Administration.

Lawrence Livermore National Laboratory

---

---

	Microinjecting recombinant rainbow trout Ea4-peptide of pro-IGF-I into zebrafish embryos causes abnormal development in heart, red blood cells, and ... Biochemistry and Physiology, Part C] by C.Z. Chun (Author), T.T. Chen (Author) This digital document is a journal article from Comparative Biochemistry and Physiology, Part C, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: E-peptides and mature insulin-like growth factors (IGFs) are produced from pre-pro-IGFs during post-translational processing and co-secreted into the circulation. Previously, we reported that introduction of a transgene encoding the secreted form of rainbow trout (rt) Ea4-peptide or human (h) Eb-peptide into newly fertilized eggs of medaka (Oryzias latipes) and zebrafish (Danio rerio) resulted in developmental defects in heart, red blood cells and vasculature. In addition to vasculature...
	Regenerating the Heart: Stem Cells and the Cardiovascular System (Stem Cell Biology and Regenerative Medicine) by Ira S. Cohen (Editor), Glenn R. Gaudette (Editor) Medical research made huge strides in treating heart disease in the 20th century, from drug-eluding stents to automatic internal defibrillators. Public awareness of the dangers of heart disease has never been more pervasive. Now, though, ten years into a new millennium, scientists are gearing up for the next great challenges in tackling this pervasive condition. Cell therapy is going to be a key weapon in the fight against heart disease. It has the potential to address many cardiovascular conditions. From heart failure to atrioventricular nodal dysfunction, the young but promising field of cell therapy is set to play a significant role in developing the cures that the upcoming decades of hard work will yield. Regenerating the Heart: Stem Cells and the Cardiovascular System...
	The Healthy Heart for Dummies by Rippe (Author) The Healthy Heart For Dummies explores that most vital organ -- the heart -- and explains why you need to care for it. This book also helps you design a personal lifestyle based on proper nutrition, physical activity, weight management, and mind/body connections to both prevent and control heart disease. It includes a section describing the latest tests and procedures used in evaluating heart health and problems, which help you make decisions on treatment options. As an added bonus, the author, James M. Rippe, M.D., has conferred with the world's top chefs to offer you 35 great tasting and heart-healthy recipes.
	Heart Physiology: From Cell to Circulation by Lionel H. Opie (Author) Thoroughly revised and updated, this Fourth Edition is the only current book that integrates cellular and subcellular elements of cardiovascular physiology in the analysis of physiologic and pathophysiologic responses. In straightforward terms, with more than 600 diagrams and illustrations, the book explains the key principles crucial to understanding how the cardiovascular system and its components function and malfunction. For this edition, Dr. Opie has enlisted eight internationally eminent co-authors and added a new chapter on cell signaling. The chapters on physiology of the ECG and arrhythmias contain many more ECGs. More than half of the illustrations—including 12 color plates—are new.
	Mechanosensitivity of the Heart (Mechanosensitivity in Cells and Tissues) by Andre Kamkin (Editor), Irina Kiseleva (Editor) This book presents the latest findings in field of research of mechanosensitivity of the heart. The Volume focuses on molecular mechanisms of mechanotransduction in cardiac cells. It contains a detailed description of several stretch-induced signaling cascades with multiple levels of crosstalk between different pathways. It highlights the role of cardiac stretch-activated channels and their contribution to cardiac performance. This book provides justification of scientific significance and potential for clinical applications of findings of fundamental investigations in the field of mechanosensitivity, which is stressed by description of reported increased sensitivity of cardiac cells to mechanical stress under various pathological conditions. It contains new insights into...
	Mesenchymal Stem Cells for the Heart: From Bench to Bedside (Advanced Topics in Science and Technology in China) by Xiaojie Xie (Editor), Jian-an Wang (Editor) Stem cell research has the potential to affect the lives of millions of people around the world. This research is now regularly front-page news, and realizing the promise of mesenchymal stem cells for yielding new medical therapies will require us to grapple with more than just scientific uncertainties. "Mesenchymal Stem Cells for the Heart - From Bench to Bedside" presents the cytobiological characteristics of mesenchymal stem cells from the isolation, culture, transmembrane ion currents, migration and differentiation in vitro to the repairing of injured myocardium and tissue reconstruction in vivo, including the results of basic research and the real possibility for treatments and ultimately for cures for cardiac diseases for which adequate therapies do not exist. The book is intended...
	Reactivation of the Cell Cycle in Terminally Differentiated Cells (Molecular Biology Intelligence Unit) by Marco Crescenzi (Editor) This volume deals with the most advanced areas of reactivation of the cell cycle in terminally differentiated cells. Terminally differentiated cells have long been regarded as irreversibly unable to proliferate. However, this view is being overturned, with great implications for both biological knowledge and potential therapeutic applications. The basic science is presented in detail and the potentialities for exploitation in cell replacement therapy and tissue repair are highlighted. For the first time, large parts of this research field are covered in a single resource, contributed by scientists who have given the most to its advancement in recent years. This volume will be valuable for young scientists wishing to enter this field and will serve as an authoritative reference for those...
	Mathematically Modeling the Electrical Activity of the Heart: From Cell to Body Surface and Back by Andrew J. Pullan (Author) This book on modelling the electrical activity of the heart is an attempt to describe continuum based modelling of cardiac electrical activity from the cell level to the body surface (the forward problem), and back again (the inverse problem). Background anatomy and physiology is covered briefly to provide a suitable context for understanding the detailed modelling that is presented herein. The questions of what is mathematical modelling and why one would want to use mathematical modelling are addressed to give some perspective to the philosophy behind our approach. Our view of mathematical modelling is broad — it is not simply about obtaining a solution to a set of mathematical equations, but includes some material on aspects such as experimental and clinical validation.
	Leading from the Heart: A Cell Leader's Guide to Passionate Ministry Do your groups need new life? Does your ministry need a spark? This book will renew your heart, refocus your priorities, and recharge your ministry as a small group leader!Powerful small group leaders share a common trait: they possess a passionate heart for God. They know their priorities and know that time with Him always tops the list. Each has a heart of brokenness before God ... a heart that is called to serve others, and a heart that pours out the love of Christ to others.If you are tired and need a spiritual boost, this book will lead you to the Source of life. And if you want to move from good to great in small group leadership, this book will take you deeper into the heart of God and help you grow.This resource has multiple uses: private reflection, group leader training, and...
	Heart Cell Communication in Health and Disease by Walmor C. de Mello (Editor), Michiel J. Janse (Editor) In Heart Cell Communication in Health and Disease an extensive review of different aspects of heart cell communication is presented. The book starts with the fundamental concept that cardiac cells are communicated, and then proceeds to the role of gap junctions in heart development, the molecular biology of gap junctions, the biophysics of the intercellular channels, the control of junctional conductance and the influence of gap junctions on impulse propagation. This is the first time that a single volume has described cell communication in the normal heart and under different pathological conditions such as heart failure, coronary disease, myocardial ischemia and cardiac arrhythmias. In this way the process of cell communication is analyzed at different levels of...