The newt and the zebrafish have the ability to regenerate many of their tissues and organs including the heart. Thus, a major goal in experimental medicine is to elucidate the molecular mechanisms underlying the regenerative capacity of these species. A wide variety of experiments have demonstrated that naturally occurring heart regeneration relies on cardiomyocyte proliferation. Thus, major ef...

Amongst animal species, there is enormous variation in the size and complexity of the heart, ranging from the simple one-chambered heart of Ciona intestinalis to the complex four-chambered heart of lunged animals. To address possible mechanisms for the evolutionary adaptation of heart size, we studied how growth of the simple two-chambered heart in zebrafish is regulated. Our data show that the...

Leone M, Magadum A, Engel FB. Cardiomyocyte proliferation in cardiac development and regeneration: a guide to methodologies and interpretations. Am J Physiol Heart Circ Physiol 309: H1237–H1250, 2015. First published September 4, 2015; doi:10.1152/ajpheart.00559.2015.—The newt and the zebrafish have the ability to regenerate many of their tissues and organs including the heart. Thus, a major go...

MicroRNAs play important roles in cell proliferation, differentiation, and apoptosis, and their expression influences cardiomyocyte apoptosis resulting from ischemia-induced myocardial infarction. Here, we determined the role of miR expression in cardiomyocyte apoptosis during hypoxia and reoxygenation. The rat cardiomyocyte cell line H9c2 was incubated for 3 h in normal or hypoxia medium, foll...

Cardiomyocyte regeneration is limited in adult life. Thus, the identification of a putative source of cardiomyocyte progenitors is of great interest to provide a usable model in vitro and new perspective in regenerative therapy. As adipose tissues were recently demonstrated to contain pluripotent stem cells, the emergence of cardiomyocyte phenotype from adipose-derived cells was investigated. W...

It is widely accepted that there are two principal forms of cell death; namely, necrosis and apoptosis. According to the classical view, necrosis is the major mechanism of cardiomyocyte death in cardiac diseases. However, in the past few years observations have been made showing that cardiomyocyte apoptosis occurs in diverse conditions and that apoptosis may be a contributing cause of the loss ...

Embryonic stem cells provide one potential source of cardiomyocytes for cardiac transplantation; however, after differentiation of stem cells in vitro, cardiomyocytes usually account for only a minority of cells present. To gain insights into improving cardiomyocyte development from stem cells, we examined the role of the Na(+)/H(+) exchanger isoform 1 (NHE1) in cardiomyocyte differentiation. N...

Prenatal exposure to high levels of ethanol is associated with cardiac malformations, but the effects of lower levels of exposure on the heart are unclear. Our aim was to investigate the effects of daily exposure to ethanol during late gestation, when cardiomyocytes are undergoing maturation, on the developing myocardium. Pregnant ewes were infused with either ethanol (0.75 g/kg) or saline for ...

Biomechanical stress on the heart results in activation of numerous signaling cascades, leading to cardiomyocyte hypertrophy, apoptosis, and ultimately, heart failure. The Ca2+-dependent phosphatase calcineurin is an essential mediator of cardiac hypertrophy, and in most but not all studies, calcineurin inhibition attenuated cardiac hypertrophy in vivo. However, calcineurin inhibition has been ...

RATIONALE Cardiomyocytes in adult mammalian hearts are terminally differentiated cells that have exited from the cell cycle and lost most of their proliferative capacity. Death of mature cardiomyocytes in pathological cardiac conditions and the lack of regeneration capacity of adult hearts are primary causes of heart failure and mortality. However, how cardiomyocyte proliferation in postnatal a...