scholarly journals Over-activation of BMP signaling in neural crest cells precipitates heart outflow tract septation

2019 ◽  
Author(s):  
Giulia Boezio
2019 ◽  
Author(s):  
Jean-François Darrigrand ◽  
Mariana Valente ◽  
Pauline Martinez ◽  
Glenda Comai ◽  
Maxime Petit ◽  
...  

SummaryEstablishment of separated pulmonary and systemic circulations in vertebrates relies on the key role of neural crest cells (NCC) for the septation of the embryonic cardiac outflow tract (OFT). Absence of NCCs induces OFT septation defects, analogous to a loss of Bone Morphogenetic Proteins (BMPs) activity, though it remains unclear how BMPs control cardiac NCC differentiation and behaviour. To address this question, we monitored cardiac NCC state upon gain in BMP signaling, caused by the deletion of Dullard, using 3D-imaging and single cell transcriptomics. Specific loss of Dullard in the NCC results in premature OFT septation, pulmonary artery obstruction and embryonic death. This is caused by uncontrolled NCC convergence towards the endocardium and asymmetrical myocardial differentiation, promoted by elevated levels of the guiding cue Sema3c and decreased levels in mesenchymal trait markers. Furthermore, we unraveled the molecular basis of the zipper-like OFT septation where graded Sema3c expression follow a gradient of BMP activation in NCC along the OFT length.


Development ◽  
1997 ◽  
Vol 124 (2) ◽  
pp. 505-514 ◽  
Author(s):  
S.J. Conway ◽  
D.J. Henderson ◽  
A.J. Copp

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.


2013 ◽  
Vol 28 (6) ◽  
pp. 1422-1433 ◽  
Author(s):  
Yoshihiro Komatsu ◽  
Paul B Yu ◽  
Nobuhiro Kamiya ◽  
Haichun Pan ◽  
Tomokazu Fukuda ◽  
...  

Development ◽  
1998 ◽  
Vol 125 (24) ◽  
pp. 4919-4930 ◽  
Author(s):  
M.A. Selleck ◽  
M.I. Garcia-Castro ◽  
K.B. Artinger ◽  
M. Bronner-Fraser

To define the timing of neural crest formation, we challenged the fate of presumptive neural crest cells by grafting notochords, Sonic Hedgehog- (Shh) or Noggin-secreting cells at different stages of neurulation in chick embryos. Notochords or Shh-secreting cells are able to prevent neural crest formation at open neural plate levels, as assayed by DiI-labeling and expression of the transcription factor, Slug, suggesting that neural crest cells are not committed to their fate at this time. In contrast, the BMP signaling antagonist, Noggin, does not repress neural crest formation at the open neural plate stage, but does so if injected into the lumen of the closing neural tube. The period of Noggin sensitivity corresponds to the time when BMPs are expressed in the dorsal neural tube but are down-regulated in the non-neural ectoderm. To confirm the timing of neural crest formation, Shh or Noggin were added to neural folds at defined times in culture. Shh inhibits neural crest production at early stages (0-5 hours in culture), whereas Noggin exerts an effect on neural crest production only later (5-10 hours in culture). Our results suggest three phases of neurulation that relate to neural crest formation: (1) an initial BMP-independent phase that can be prevented by Shh-mediated signals from the notochord; (2) an intermediate BMP-dependent phase around the time of neural tube closure, when BMP-4 is expressed in the dorsal neural tube; and (3) a later pre-migratory phase which is refractory to exogenous Shh and Noggin.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Jean-François Darrigrand ◽  
Mariana Valente ◽  
Glenda Comai ◽  
Pauline Martinez ◽  
Maxime Petit ◽  
...  

The establishment of separated pulmonary and systemic circulation in vertebrates, via cardiac outflow tract (OFT) septation, is a sensitive developmental process accounting for 10% of all congenital anomalies. Neural Crest Cells (NCC) colonising the heart condensate along the primitive endocardial tube and force its scission into two tubes. Here, we show that NCC aggregation progressively decreases along the OFT distal-proximal axis following a BMP signalling gradient. Dullard, a nuclear phosphatase, tunes the BMP gradient amplitude and prevents NCC premature condensation. Dullard maintains transcriptional programs providing NCC with mesenchymal traits. It attenuates the expression of the aggregation factor Sema3c and conversely promotes that of the epithelial-mesenchymal transition driver Twist1. Altogether, Dullard-mediated fine-tuning of BMP signalling ensures the timed and progressive zipper-like closure of the OFT by the NCC and prevents the formation of a heart carrying the congenital abnormalities defining the tetralogy of Fallot.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Kathleen M Ruppel ◽  
Hiroshi Kataoka ◽  
Michelle Iwaki ◽  
Ivo Cornelissen ◽  
Shaun R Coughlin

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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