TY - JOUR
T1 - Tbx1 coordinates addition of posterior second heart field progenitor cells to the arterial and venous poles of the heart
AU - Rana, M. Sameer
AU - Théveniau-Ruissy, Magali
AU - De Bono, Christopher
AU - Mesbah, Karim
AU - Francou, Alexandre
AU - Rammah, Mayyasa
AU - Domínguez, Jorge N.
AU - Roux, Marine
AU - Laforest, Brigitte
AU - Anderson, Robert H.
AU - Mohun, Timothy
AU - Zaffran, Stephane
AU - Christoffels, Vincent M.
AU - Kelly, Robert G.
N1 - Publisher Copyright:
© 2014 American Heart Association, Inc.
PY - 2014
Y1 - 2014
N2 - Rationale: Cardiac progenitor cells from the second heart field (SHF) contribute to rapid growth of the embryonic heart, giving rise to right ventricular and outflow tract (OFT) myocardium at the arterial pole of the heart, and atrial myocardium at the venous pole. Recent clonal analysis and cell-tracing experiments indicate that a common progenitor pool in the posterior region of the SHF gives rise to both OFT and atrial myocytes. The mechanisms regulating deployment of this progenitor pool remain unknown. Objective: To evaluate the role of TBX1, the major gene implicated in congenital heart defects in 22q11.2 deletion syndrome patients, in posterior SHF development. Methods and Results: Using transcriptome analysis, genetic tracing, and fluorescent dye-labeling experiments, we show that Tbx1-dependent OFT myocardium originates in Hox-expressing cells in the posterior SHF. In Tbx1 null embryos, OFT progenitor cells fail to segregate from this progenitor cell pool, leading to failure to expand the dorsal pericardial wall and altered positioning of the cardiac poles. Unexpectedly, addition of SHF cells to the venous pole of the heart is also impaired, resulting in abnormal development of the dorsal mesenchymal protrusion, and partially penetrant atrioventricular septal defects, including ostium primum defects. Conclusions: Tbx1 is required for inflow as well as OFT morphogenesis by regulating the segregation and deployment of progenitor cells in the posterior SHF. Our results provide new insights into the pathogenesis of congenital heart defects and 22q11.2 deletion syndrome phenotypes. (Circ Res. 2014;115:790-799.)
AB - Rationale: Cardiac progenitor cells from the second heart field (SHF) contribute to rapid growth of the embryonic heart, giving rise to right ventricular and outflow tract (OFT) myocardium at the arterial pole of the heart, and atrial myocardium at the venous pole. Recent clonal analysis and cell-tracing experiments indicate that a common progenitor pool in the posterior region of the SHF gives rise to both OFT and atrial myocytes. The mechanisms regulating deployment of this progenitor pool remain unknown. Objective: To evaluate the role of TBX1, the major gene implicated in congenital heart defects in 22q11.2 deletion syndrome patients, in posterior SHF development. Methods and Results: Using transcriptome analysis, genetic tracing, and fluorescent dye-labeling experiments, we show that Tbx1-dependent OFT myocardium originates in Hox-expressing cells in the posterior SHF. In Tbx1 null embryos, OFT progenitor cells fail to segregate from this progenitor cell pool, leading to failure to expand the dorsal pericardial wall and altered positioning of the cardiac poles. Unexpectedly, addition of SHF cells to the venous pole of the heart is also impaired, resulting in abnormal development of the dorsal mesenchymal protrusion, and partially penetrant atrioventricular septal defects, including ostium primum defects. Conclusions: Tbx1 is required for inflow as well as OFT morphogenesis by regulating the segregation and deployment of progenitor cells in the posterior SHF. Our results provide new insights into the pathogenesis of congenital heart defects and 22q11.2 deletion syndrome phenotypes. (Circ Res. 2014;115:790-799.)
KW - Congenital
KW - DiGeorge syndrome
KW - Heart defects
KW - Mouse
KW - Tbx1 protein
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U2 - 10.1161/CIRCRESAHA.115.305020
DO - 10.1161/CIRCRESAHA.115.305020
M3 - Article
C2 - 25190705
AN - SCOPUS:84921997239
SN - 0009-7330
VL - 115
SP - 790
EP - 799
JO - Circulation research
JF - Circulation research
IS - 9
ER -