Neocardiogenesis
Encyclopedia
In cardiology neocardiogenesis is the homeostatic regeneration, repair and renewal of sections of malfunctioning adult cardiovascular tissue. This includes a combination of cardiomyogenesis (the regeneration of cardiac muscle
) and angiogenesis
(the regeneration of blood vessels).
, which refers to the development of the heart in the embryo; neocardiogenesis, in turn, means the development of the heart in adults. The heart has mechanisms already in place that are responsible for small scale repair. However, these repair mechanisms are not sufficient for large scale repair, made necessary by events such as myocardial infarctions. Neocardiogenesis replaces dead cardiac muscle cells with living cells so that both the structure and function of the heart are maintained. This improves myocardial pumping of fluid around the body.
. These cells are activated by a mixture of transcriptional factors, genes, growth factors, receptors, the extracellular matrix
and signalling pathways. The cells then move to affected areas where they can reverse some of the damage by generating a new population of cardiomyocytes.
Cardiac muscle
Cardiac muscle is a type of involuntary striated muscle found in the walls and histologic foundation of the heart, specifically the myocardium. Cardiac muscle is one of three major types of muscle, the others being skeletal and smooth muscle...
) and angiogenesis
Angiogenesis
Angiogenesis is the physiological process involving the growth of new blood vessels from pre-existing vessels. Though there has been some debate over terminology, vasculogenesis is the term used for spontaneous blood-vessel formation, and intussusception is the term for the formation of new blood...
(the regeneration of blood vessels).
Definition and Scope
The term neocardiogenesis comes from cardiogenesisCardiogenesis
Cardiogenesis Corporation is a medical device company specializing in products for the treatment of chronic cardiac ischemia.The company's Ho:YAG laser system and disposable fiber-optic accessories are used to perform an FDA-cleared surgical procedure known as Transmyocardial revascularization...
, which refers to the development of the heart in the embryo; neocardiogenesis, in turn, means the development of the heart in adults. The heart has mechanisms already in place that are responsible for small scale repair. However, these repair mechanisms are not sufficient for large scale repair, made necessary by events such as myocardial infarctions. Neocardiogenesis replaces dead cardiac muscle cells with living cells so that both the structure and function of the heart are maintained. This improves myocardial pumping of fluid around the body.
Background
The human heart has been thought of as a postmitotic organ. Cardiomyocytes (muscle cells of the heart) were thought to be terminally differentiated cells that were irreplaceable and thus required to maintain cardiac function throughout life. However it is now known that the heart is able to regenerate new small vessels needed to repair an ischemic (lacking blood) myocardium. The belief that humans are born with a fixed number of cardiomyocytes, and that the growth of these cells was directly responsible for the growth of the heart, has also been disproven. Reports of the heart's ability to repair itself have started to appear in peer reviewed journals and a paper has been published that has shown the potential of bone marrow cells to regenerate myocardium (myogenesis). Other studies into the regeneration of myocardium have highlighted evidence of angiogenesis. It has been reported that improvement in heart contractility has occurred as a result of the induction of angiogenesis. The results of these studies suggest that there is a possibility that, during neocardiogenesis, angiogenesis and myogenesis are interlinked and operate simultaneously in the process of cardiac regeneration. The possibility of such a linkage necessitates more research into the areas surrounding this phenomenon. There is also the need for a clearer definition of neocardiogenesis.Mechanism
The activation of cardiac progenitor cells (a special type of stem cell with long telomeres located in the storage areas of the heart) and circulating stem cells induce cardiomyocytes to proliferateCell growth
The term cell growth is used in the contexts of cell development and cell division . When used in the context of cell division, it refers to growth of cell populations, where one cell grows and divides to produce two "daughter cells"...
. These cells are activated by a mixture of transcriptional factors, genes, growth factors, receptors, the extracellular matrix
Extracellular matrix
In biology, the extracellular matrix is the extracellular part of animal tissue that usually provides structural support to the animal cells in addition to performing various other important functions. The extracellular matrix is the defining feature of connective tissue in animals.Extracellular...
and signalling pathways. The cells then move to affected areas where they can reverse some of the damage by generating a new population of cardiomyocytes.