| Titre : | Myocardial progenitor cells in the early embryo |
| contenu dans : | |
| Auteurs : | Congrès international de myologie 2008 (International Congress of Myology 2008; 26-30 mai 2008; Marseille, France) ; Kelly RG |
| Type de document : | Article |
| Année de publication : | 2008 |
| Pages : | p. 22 |
| Langues: | Anglais |
| Mots-clés : | cellule souche ; croissance musculaire ; différenciation cellulaire ; embryologie ; facteur de croissance ; facteur de transcription ; fibre musculaire cardiaque ; gène ; muscle masticateur ; mutation génétique ; myocarde ; prolifération cellulaire |
| Résumé : | The embryonic heart grows by addition of progenitor cells of the recently identified second heart field to the arterial and venous poles of the cardiac tube. Second heart field cells are situated in pharyngeal mesoderm and characterized by differentiation delay and the expression of genes encoding the transcription factors Isl1 and Tbx1 and growth factors Fgf8 and Fgf10. Pharyngeal mesoderm also contains branchiomeric skeletal muscle progenitor cells that give rise to the muscles of mastication, facial expression and laryngeal and pharyngeal muscles. The genetic program of branchiomeric skeletal muscle progenitor cells differs from that of all other skeletal muscles and overlaps with that of the second heart field. Isl1 positive cells have been identified in fetal and postnatal hearts where they have been shown to be multipotent resident cardiac stem cells. The transcription factors and signaling pathways regulating second heart field proliferation and differentiation remain poorly understood. We have identified a subpopulation of the second heart field dependent on the transcription factor Tbx1, major candidate gene for del22q11.2 or DiGeorge syndrome. Loss of this cell population, normally giving rise to subpulmonary myocardium, is associated with anomalous coronary artery patterning in mutant embryos. Loss of a second T-box containing transcription factor, Tbx3, impacts indirectly on second heart field proliferation, providing evidence for interactions between the second heart field and adjacent neural crest cells during heart tube elongation. Characterization of the intrinsic and extrinsic regulators of second heart field development will contribute to our understanding of the origins of congenital heart defects and the properties of cardiac progenitor cells in the early embryo and fetal heart. |
MYOBASE
Portail documentaire sur les maladies neuromusculaires
Se connecter
Accueil
Sélection de la langue
Adresse
MYOBASEcontact