Mis-Expression of a Cranial Neural Crest Cell-Specific Gene Program in Cardiac Neural Crest Cells Modulates HAND Factor Expression, Causing Cardiac Outflow Tract Phenotypes

Congenital heart defects (CHDs) occur with such a frequency that they constitute a significant cause of morbidity and mortality in both children and adults. A significant portion of CHDs can be attributed to aberrant development of the cardiac outflow tract (OFT), and of one of its cellular progenitors known as the cardiac neural crest cells (NCCs). The gene regulatory networks that identify cardiac NCCs as a distinct NCC population are not completely understood. Heart and neural crest derivatives (HAND) bHLH transcription factors play essential roles in NCC morphogenesis. The Hand1PA/OFT enhancer is dependent upon bone morphogenic protein (BMP) signaling in both cranial and cardiac NCCs. The Hand1PA/OFT enhancer is directly repressed by the endothelin-induced transcription factors DLX5 and DLX6 in cranial but not cardiac NCCs. This transcriptional distinction offers the unique opportunity to interrogate NCC specification, and to understand why, despite similarities, cranial NCC fate determination is so diverse. We generated a conditionally active transgene that can ectopically express DLX5 within the developing mouse embryo in a Cre-recombinase-dependent manner. Ectopic DLX5 expression represses cranial NCC Hand1PA/OFT-lacZ reporter expression more effectively than cardiac NCC reporter expression. Ectopic DLX5 expression induces broad domains of NCC cell death within the cranial pharyngeal arches, but minimal cell death in cardiac NCC populations. This study shows that transcription control of NCC gene regulatory programs is influenced by their initial specification at the dorsal neural tube.

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Pax3 is required for cardiac neural crest migration in the mouse: evidence from the splotch (Sp2H) mutant

Development ◽

10.1242/dev.124.2.505 ◽

1997 ◽

Vol 124 (2) ◽

pp. 505-514 ◽

Cited By ~ 14

Author(s):

S.J. Conway ◽

D.J. Henderson ◽

A.J. Copp

Keyword(s):

Neural Crest ◽

Neural Tube ◽

Neural Crest Cells ◽

Outflow Tract ◽

Avian Embryo ◽

Cardiac Neural Crest ◽

Branchial Arches ◽

Aortic Arches ◽

Cardiac Outflow

Neural crest cells originating in the occipital region of the avian embryo are known to play a vital role in formation of the septum of the cardiac outflow tract and to contribute cells to the aortic arches, thymus, thyroid and parathyroids. This ‘cardiac’ neural crest sub-population is assumed to exist in mammals, but without direct evidence. In this paper we demonstrate, using RT-PCR and in situ hybridisation, that Pax3 expression can serve as a marker of cardiac neural crest cells in the mouse embryo. Cells of this lineage were traced from the occipital neural tube, via branchial arches 3, 4 and 6, into the aortic sac and aorto-pulmonary outflow tract. Confirmation that these Pax3-positive cells are indeed cardiac neural crest is provided by experiments in which hearts were deprived of a source of colonising neural crest, by organ culture in vitro, with consequent lack of up-regulation of Pax3. Occipital neural crest cell outgrowths in vitro were also shown to express Pax3. Mutation of Pax3, as occurs in the splotch (Sp2H) mouse, results in development of conotruncal heart defects including persistent truncus arteriosus. Homozygotes also exhibit defects of the aortic arches, thymus, thyroid and parathyroids. Pax3-positive neural crest cells were found to emigrate from the occipital neural tube of Sp2H/Sp2H embryos in a relatively normal fashion, but there was a marked deficiency or absence of neural crest cells traversing branchial arches 3, 4 and 6, and entering the cardiac outflow tract. This decreased expression of Pax3 in Sp2H/Sp2H embryos was not due to down-regulation of Pax3 in neural crest cells, as use of independent neural crest markers, Hoxa-3, CrabpI, Prx1, Prx2 and c-met also revealed a deficiency of migrating cardiac neural crest cells in homozygous embryos. This work demonstrates the essential role of the cardiac neural crest in formation of the heart and great vessels in the mouse and, furthermore, shows that Pax3 function is required for the cardiac neural crest to complete its migration to the developing heart.

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Cardiac Neural Crest Cells Provide New Insight into Septation of the Cardiac Outflow Tract: Aortic Sac to Ventricular Septal Closure

Developmental Biology ◽

10.1006/dbio.1998.8860 ◽

1998 ◽

Vol 196 (2) ◽

pp. 129-144 ◽

Cited By ~ 198

Author(s):

Karen Waldo ◽

Sachiko Miyagawa-Tomita ◽

Donna Kumiski ◽

Margaret L. Kirby

Keyword(s):

Neural Crest ◽

Neural Crest Cells ◽

Outflow Tract ◽

Cardiac Neural Crest ◽

Insight Into ◽

Cardiac Outflow

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BMP receptor IA is required in mammalian neural crest cells for development of the cardiac outflow tract and ventricular myocardium

Development ◽

10.1242/dev.01086 ◽

2004 ◽

Vol 131 (9) ◽

pp. 2205-2218 ◽

Cited By ~ 125

Author(s):

R. W. Stottmann

Keyword(s):

Neural Crest ◽

Neural Crest Cells ◽

Ventricular Myocardium ◽

Outflow Tract ◽

Bmp Receptor ◽

Cardiac Outflow

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Faculty Opinions recommendation of Histone deacetylase 3 regulates smooth muscle differentiation in neural crest cells and development of the cardiac outflow tract.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.13336060.14702197 ◽

2011 ◽

Author(s):

Stephen Schwartz

Keyword(s):

Smooth Muscle ◽

Neural Crest ◽

Histone Deacetylase ◽

Neural Crest Cells ◽

Muscle Differentiation ◽

Outflow Tract ◽

Histone Deacetylase 3 ◽

Smooth Muscle Differentiation ◽

Cardiac Outflow

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Decision letter: Dullard-mediated Smad1/5/8 inhibition controls mouse cardiac neural crest cells condensation and outflow tract septation

10.7554/elife.50325.sa1 ◽

2019 ◽

Keyword(s):

Neural Crest ◽

Neural Crest Cells ◽

Outflow Tract ◽

Cardiac Neural Crest

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Abstract 939: Galpha-i Signaling in Neural Crest Cells is Required for Normal Migration of Cardiac Neural Crest Cells, Cardiac Development, and Survival

Circulation ◽

10.1161/circ.116.suppl_16.ii_185-b ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Kathleen M Ruppel ◽

Hiroshi Kataoka ◽

Michelle Iwaki ◽

Ivo Cornelissen ◽

Shaun R Coughlin

Keyword(s):

Neural Crest ◽

Signaling Pathways ◽

Aortic Arch ◽

G Protein ◽

Heart Defects ◽

Neural Crest Cells ◽

Outflow Tract ◽

Potential Candidate ◽

Dependent Manner ◽

Cardiovascular Development

G protein coupled receptors (GPCRs) have long been known to play crucial roles in transducing environmental signals to the adult cardiovascular system. In recent years, the roles of G protein-mediated signaling pathways in orchestrating the interactions of different tissues during cardiovascular development have become increasingly evident. To analyze the role of G protein signaling pathways in vivo we have generated mice where the function of the heterotrimeric G alpha subunit Gai can be ablated in a cell type specific manner utilizing the Cre-loxP system. We have mated these mice to two different neural crest-specific Cre lines in order to probe the effects of loss of Gai mediated signaling on the ability of neural crest cells (NCC) to contribute to the developing outflow tract and aortic arch arteries. METHODS: We have generated mice that express the Gai-inhibiting pertussis toxin S1 subunit (PTX) from the ROSA26 locus in a Cre recombination dependent manner (ROSA-PTX mice). These were mated to mice expressing either the Wnt1 Cre or P0 Cre transgene. Wnt1Cre is active in both premigratory and migratory NCC, whereas P0Cre is active only in migratory NCC and their derivatives. RESULTS: P0Cre-ROSA-PTX mice were normal at birth and demonstrated no structural heart defects. In contrast, Wnt1Cre-ROSA-PTX mice were present in normal numbers at late gestation but died perinatally due in part to cardiac outflow tract defects. Excision reporter and in situ hybridization studies suggest this is secondary to a delay/blockage of cardiac NCC migration into the developing outflow tract. NCC migration into the pharyngeal arches was unaffected in these mice and no craniofacial, thymic, or aortic arch abnormalities were observed. CONCLUSIONS: These results indicate that Gai-mediated signaling is required in premigratory or early migratory cardiac NCC for normal development of the outflow tract. In contrast, endothelin A receptor knockout mice (currently the only GPCR knock out with a neural crest phenotype) are thought to exhibit defects of postmigratory NCC function. RNA profiling of NCC for GPCRs involved in this Gai-dependent pathway has revealed several potential candidate receptors, including orphan receptors. Further analysis of these receptors is underway.

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