J. Cardiovasc. Dev. Dis.2014, 1(1), 73-82; doi:10.3390/jcdd1010073 - published online 10 April 2014 Show/Hide Abstract
Abstract: Cardiac regeneration remains a clinical target regardless of numerous therapeutic concepts. We formulated a hypothesis claiming that periodic coronary venous pressure elevation (PICSO; Pressure controlled Intermittent Coronary Sinus Occlusion) initiates embedded, but dormant developmental processes in adult jeopardized hearts. Hemodynamics in the primitive beating heart tube is sensed transducing “mechanical” epigenetic information during normal cardiac development. In analogy mechanotransduction via shear stress and pulsatile stretch induced by periodic elevation of blood pressure in cardiac veins reconnects this dormant developmental signal, setting regenerative impulses in the adult heart. Significant increase of hemeoxygenase-1 gene expression (p < 0.001) and vascular endothelial growth factor (VEGF) (p < 0.002) as well as production of VEGRF2 in experimental infarction underscores the resurgence of developmental stimuli by PICSO. Molecular findings correspond with risk reduction (p < 0.0001) in patients with acute coronary syndromes as well as observations in heart failure patients showing substantial risk reduction up to 5 years endorsing our hypothesis and preclinical experience that PICSO via hemodynamic power activates regenerative processes also in adult human hearts. These results emphasize that our proposed hypothesis “embryonic recall” claiming revival of an imbedded albeit dormant “epigenetic” process is able not only to sculpture myocardium in the embryo, but also to redesign structure in the adult and failing heart.
J. Cardiovasc. Dev. Dis.2014, 1(1), 52-72; doi:10.3390/jcdd1010052 - published online 8 April 2014 Show/Hide Abstract
Abstract: Many aspects of heart development are determined by the left right axis and as a result several congenital diseases have their origins in aberrant left-right patterning. Establishment of this axis occurs early in embryogenesis before formation of the linear heart tube yet impacts upon much later morphogenetic events. In this review I discuss the differing mechanisms by which left-right polarity is achieved in the mouse and chick embryos and comment on the evolution of this system. I then discus three major classes of cardiovascular defect associated with aberrant left-right patterning seen in mouse mutants and human disease. I describe phenotypes associated with the determination of atrial identity and venous connections, looping morphogenesis of the heart tube and finally the asymmetric remodelling of the embryonic branchial arch arterial system to form the leftward looped arch of aorta and associated great arteries. Where appropriate, I consider left right patterning defects from an evolutionary perspective, demonstrating how developmental processes have been modified in species over time and illustrating how comparative embryology can aide in our understanding of congenital heart disease.
J. Cardiovasc. Dev. Dis.2014, 1(1), 41-51; doi:10.3390/jcdd1010041 - published online 31 March 2014 Show/Hide Abstract
Abstract: Diverse types of stem cells represent a potentially attractive source of cardiac cells for the treatment of cardiovascular diseases. However, most of the functional benefits reported for stem cell have been modest and mainly due to paracrine effects rather than differentiation into cardiomyocytes of the applied cells. Therefore, new tools need to be developed in order to improve the efficiency of stem cell differentiation towards specific cardiovascular lineages. Here we show that microRNAs that display early differential expression during ventricular maturation, such as miR-27b, inhibits cardiac differentiation from mouse embryonic stem cells whereas miRNAs that display late differential expression, such as miR-23b, regulates the beating phenotype during in vitro cardiac differentiation from Embryonic Stem Cells (ESCs). This study could have an impact on regenerative medicine since we showed that miR-27b and miR-23b overexpression differentially modify the ESC cell fate towards the cardiac lineage.
J. Cardiovasc. Dev. Dis.2014, 1(1), 37-40; doi:10.3390/jcdd1010037 - published online 27 March 2014 Show/Hide Abstract
Abstract: The articles and reviews in this inaugural edition of the Journal of Cardiovascular Development and Disease have been written by presenters at the 2013 Meeting of the European Society of Cardiology’s Working Group (WG) on Development, Anatomy and Pathology. The WG meeting provides an annual forum for researchers and clinicians interested in cardiac development and pathology to exchange expertise and present and debate new results, with the goal of furthering our understanding of the origins of congenital heart defects and cardiac pathology. Here we introduce the WG through a short account of the WG’s history and current activities.
J. Cardiovasc. Dev. Dis.2014, 1(1), 29-36; doi:10.3390/jcdd1010029 - published online 26 March 2014 Show/Hide Abstract
Abstract: Immediately following birth, the mammalian heart switches from generating ATP via glycolysis to β-oxidation of lipid. Coincident with this metabolic remodeling, cardiomyocyte mitosis ceases and regenerative capacity is lost. Recently, our understanding of the molecular pathways linking physiological stimuli with gene expression and phenotype changes around birth has increased, although fundamental gaps remain. This review discusses recent work that sheds light on this important area of mammalian cardiovascular development.
J. Cardiovasc. Dev. Dis.2014, 1(1), 14-28; doi:10.3390/jcdd1010014 - published online 21 March 2014 Show/Hide Abstract
Abstract: The sinus venosus, the cardiac chamber upstream of the (right) atrium, is a severely underinvestigated structure. Yet, its myocardium harbors the cardiac pacemaker in all vertebrates. In human, ectopic pacemaking and subsequent pathologies may originate from sinus venosus-derived myocardium surrounding the coronary sinus and the superior caval vein. In ectothermic vertebrates, i.e., fishes, amphibians and reptiles, the sinus venosus aids atrial filling by contracting prior to the atrium (atria). This is facilitated by the sinuatrial delay of approximately the same duration as the atrioventricular delay, which facilitates atrial filling of the ventricles. In mammals, the sinuatrial delay is lost, and the sinus venosus-derived myocardium persists as an extensive myocardial sheet surrounding the caval veins, which is activated in synchrony with the myocardium of the atria. The caval vein myocardium is hardly of significance in the healthy formed heart, but we suggest that the sinus venosus functions as a chamber during development when cardiac output, heart rate, blood pressure and architecture is much more like that of ectothermic vertebrates. The remodeling of the sinus venosus in mammals may be an adaptation associated with the high heart rates necessary for postnatal endothermy. If so, the endothermic birds should exhibit a similar remodeling as mammals, which remains to be investigated.