Shaping the mouse heart tube from the second heart field epithelium

The embryonic heart forms in anterior lateral splanchnic mesoderm and is derived from Mesp1-expressing progenitor cells. During embryonic folding, the earliest differentiating progenitor cells form the linear heart tube in the ventral midline. The heart tube extends in length and loops to the right as new myocardium is progressively added at the venous and arterial poles from multipotent second heart field cardiovascular progenitor cells in contiguous pharyngeal mesoderm. While the linear heart tube gives rise to the left ventricle, the right ventricle, outflow tract, and a large part of atrial myocardium are derived from the second heart field. Progressive myocardial differentiation is controlled by intercellular signals within the progenitor cell niche. The embryonic heart is the template for septation and growth of the four-chambered definitive heart and defects in progenitor cell deployment result in a spectrum of common forms of congenital heart defects.

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Cardiac embryogenesis

ESC CardioMed ◽

10.1093/med/9780198784906.003.0004 ◽

2018 ◽

pp. 33-36

Author(s):

Robert G. Kelly

Keyword(s):

Progenitor Cells ◽

Progenitor Cell ◽

Congenital Heart ◽

Heart Defects ◽

Embryonic Heart ◽

Heart Tube ◽

Second Heart Field ◽

Heart Field ◽

Cell Niche ◽

The Right

The embryonic heart forms in anterior lateral splanchnic mesoderm and is derived from Mesp1-expressing progenitor cells. During embryonic folding, the earliest differentiating progenitor cells form the linear heart tube in the ventral midline. The heart tube extends in length and loops to the right as new myocardium is progressively added at the venous and arterial poles from multipotent second heart field cardiovascular progenitor cells in contiguous pharyngeal mesoderm. While the linear heart tube gives rise to the left ventricle, the right ventricle, outflow tract, and a large part of atrial myocardium are derived from the second heart field. Progressive myocardial differentiation is controlled by intercellular signals within the progenitor cell niche. The embryonic heart is the template for septation and growth of the four-chambered definitive heart and defects in progenitor cell deployment result in a spectrum of common forms of congenital heart defects.

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A Role for the Cytoskeleton in Heart Looping

The Scientific World JOURNAL ◽

10.1100/tsw.2007.87 ◽

2007 ◽

Vol 7 ◽

pp. 280-298 ◽

Cited By ~ 23

Author(s):

Kersti K. Linask ◽

Michael VanAuker

Keyword(s):

Heart Development ◽

Cell Biology ◽

Heart Defects ◽

Heart Tube ◽

Second Heart Field ◽

The Past ◽

Complex Process ◽

Nonmuscle Myosin Ii ◽

Heart Looping ◽

Heart Field

Over the past 10 years, key genes involved in specification of left-right laterality pathways in the embryo have been defined. The read-out for misexpression of laterality genes is usually the direction of heart looping. The question of how dextral looping direction occurred mechanistically and how the heart tube bends remains unknown. It is becoming clear from our experiments and those of others that left-right differences in cell proliferation in the second heart field (anterior heart field) drives the dextral direction. Evidence is accumulating that the cytoskeleton is at the center of laterality, and the bending and rotational forces associated with heart looping. If laterality pathways are modulated upstream, the cytoskeleton, including nonmuscle myosin II (NMHC-II), is altered downstream within the cardiomyocytes, leading to looping abnormalities. The cytoskeleton is associated with important mechanosensing and signaling pathways in cell biology and development. The initiation of blood flow during the looping period and the inherent stresses associated with increasing volumes of blood flowing into the heart may help to potentiate the process. In recent years, the steps involved in this central and complex process of heart development that is the basis of numerous congenital heart defects are being unraveled.

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An Appreciation of Anatomy in the Molecular World

Journal of Cardiovascular Development and Disease ◽

10.3390/jcdd7040044 ◽

2020 ◽

Vol 7 (4) ◽

pp. 44

Author(s):

Bjarke Jensen ◽

Vincent M. Christoffels ◽

Antoon F. M. Moorman

Keyword(s):

Cardiac Development ◽

Heart Diseases ◽

Molecular Techniques ◽

Regional Differentiation ◽

Heart Tube ◽

Proper Understanding ◽

Second Heart Field ◽

Heart Field ◽

Differentiation And Proliferation ◽

Special Case

Robert H. Anderson is one of the most important and accomplished cardiac anatomists of the last decades, having made major contributions to our understanding of the anatomy of normal hearts and the pathologies of acquired and congenital heart diseases. While cardiac anatomy as a research discipline has become largely subservient to molecular biology, anatomists like Professor Anderson demonstrate anatomy has much to offer. Here, we provide cases of early anatomical insights on the heart that were rediscovered, and expanded on, by molecular techniques: migration of neural crest cells to the heart was deduced from histological observations (1908) and independently shown again with experimental interventions; pharyngeal mesoderm is added to the embryonic heart (1973) in what is now defined as the molecularly distinguishable second heart field; chambers develop from the heart tube as regional pouches in what is now considered the ballooning model by the molecular identification of regional differentiation and proliferation. The anatomical discovery of the conduction system by Purkinje, His, Tawara, Keith, and Flack is a special case because the main findings were never neglected in later molecular studies. Professor Anderson has successfully demonstrated that sound knowledge of anatomy is indispensable for proper understanding of cardiac development.

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Outflow Tract Formation—Embryonic Origins of Conotruncal Congenital Heart Disease

Journal of Cardiovascular Development and Disease ◽

10.3390/jcdd8040042 ◽

2021 ◽

Vol 8 (4) ◽

pp. 42

Author(s):

Sonia Stefanovic ◽

Heather C. Etchevers ◽

Stéphane Zaffran

Keyword(s):

Congenital Heart ◽

Cardiac Development ◽

Heart Defects ◽

Dynamic Structure ◽

Cell Types ◽

Outflow Tract ◽

Heart Tube ◽

Heart Field ◽

Multiple Cell ◽

The Many

Anomalies in the cardiac outflow tract (OFT) are among the most frequent congenital heart defects (CHDs). During embryogenesis, the cardiac OFT is a dynamic structure at the arterial pole of the heart. Heart tube elongation occurs by addition of cells from pharyngeal, splanchnic mesoderm to both ends. These progenitor cells, termed the second heart field (SHF), were first identified twenty years ago as essential to the growth of the forming heart tube and major contributors to the OFT. Perturbation of SHF development results in common forms of CHDs, including anomalies of the great arteries. OFT development also depends on paracrine interactions between multiple cell types, including myocardial, endocardial and neural crest lineages. In this publication, dedicated to Professor Andriana Gittenberger-De Groot and her contributions to the field of cardiac development and CHDs, we review some of her pioneering studies of OFT development with particular interest in the diverse origins of the many cell types that contribute to the OFT. We also discuss the clinical implications of selected key findings for our understanding of the etiology of CHDs and particularly OFT malformations.

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Abstract 290: Haemogenic Endocardium Contribute To Definitive Hematopoiesis During Cardiogenesis

Circulation Research ◽

10.1161/res.113.suppl_1.a290 ◽

2013 ◽

Vol 113 (suppl_1) ◽

Author(s):

Haruko Nakano ◽

Xiaoqian Liu ◽

Armin Arshi ◽

Ben van Handel ◽

Rajkumar Sasidharan ◽

...

Keyword(s):

De Novo ◽

Ex Vivo ◽

Embryonic Stem ◽

Circulatory System ◽

Lineage Tracing ◽

Mouse Heart ◽

Heart Tube ◽

Cardiac Progenitors ◽

Definitive Hematopoiesis

The circulatory system is the first functional organ system that develops during mammalian life. Accumulating evidences suggest that cardiac and endocardial cells can arise from a single common progenitor cell during mammalian cardiogenesis. Notably, these early cardiac progenitors express multiple hematopoietic transcription factors, consistent with previous reports. Indeed, a close relationship among cardiac, endocardial and hematopoietic lineages has been suggested in fly, zebrafish, and embryonic stem cell in vitro differentiation models. However, it is unclear when, where and how this hematopoietic gene program is in operation during in vivo mammalian cardiogenesis. Hematopoietic colony assay suggests that mouse heart explants generate myeloids and erythroids in the absence of circulation, suggesting that the heart tube is a de novo site for the definitive hematopoiesis. Lineage tracing revealed that putative cardiac-derived Nkx2-5+/Isl1+ endocardial cells give rise to CD41+ hematopoietic progenitors that contribute to definitive hematopoiesis in vivo and ex vivo during embryogenesis earlier than in the AGM region. Furthermore, Nkx2-5 and Isl1 are both required for the hemogenic activity of the endocardium. Together, identification of Nkx2-5/Isl1-dependent hemogenic endocardial cells (1) adds hematopoietic component in the cardiogenesis lineage tree, (2) changes the long-held dogma that AGM is the only major source of definitive hematopoiesis in the embryo proper, and (3) represents phylogenetically conserved fundamental mechanism of cardio-vasculo-hematopoietic differentiation pathway during the development of circulatory system.

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Lamb1a regulates atrial growth by limiting excessive, contractility-dependent second heart field addition during zebrafish heart development

10.1101/2021.03.10.434727 ◽

2021 ◽

Author(s):

Christopher J. Derrick ◽

Eric J. G. Pollitt ◽

Ashley Sanchez Sevilla Uruchurtu ◽

Farah Hussein ◽

Emily S. Noёl

Keyword(s):

Heart Development ◽

Cardiac Development ◽

Basement Membranes ◽

Atrioventricular Canal ◽

Cardiac Morphogenesis ◽

Heart Morphogenesis ◽

Second Heart Field ◽

Heart Field ◽

Heart Size ◽

Zebrafish Heart

AbstractDuring early vertebrate heart development, the heart transitions from a linear tube to a complex asymmetric structure. This process includes looping of the tube and ballooning of the emerging cardiac chambers, which occur simultaneously with growth of the heart. A key driver of cardiac growth is deployment of cells from the Second Heart Field (SHF) into both poles of the heart, with cardiac morphogenesis and growth intimately linked in heart development. Laminin is a core component of extracellular matrix (ECM) basement membranes, and although mutations in specific laminin subunits are linked with a variety of cardiac abnormalities, including congenital heart disease and dilated cardiomyopathy, no role for laminin has been identified in early vertebrate heart morphogenesis. We identified dynamic, tissue-specific expression of laminin subunit genes in the developing zebrafish heart, supporting a role for laminins in heart morphogenesis.lamb1amutants exhibit cardiomegaly from 2dpf onwards, with subsequent progressive defects in cardiac morphogenesis characterised by a failure of the chambers to compact around the developing atrioventricular canal. We show that loss oflamb1aresults in excess addition of SHF cells to the atrium, revealing that Lamb1a functions to limit heart size during cardiac development by restricting SHF addition to the venous pole.lamb1amutants exhibit hallmarks of altered haemodynamics, and specifically blocking cardiac contractility inlamb1amutants rescues heart size and atrial SHF addition. Furthermore, we identify that FGF and RA signalling, two conserved pathways promoting SHF addition, are regulated by heart contractility and are dysregulated inlamb1amutants, suggesting that laminin mediates interactions between SHF deployment, heart biomechanics, and biochemical signalling during heart development. Together, this describes the first requirement for laminins in early vertebrate heart morphogenesis, reinforcing the importance of specialised ECM composition in cardiac development.

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