title: Origin of coronary endothelial cells from epicardial mesothelium in avian embryos.
abstract: It has been established that coronary vessels develop through self-assembly of mesenchymal vascular progenitors in the subepicardium. Mesenchymal precursors of vascular smooth muscle cells and fibroblasts are known to originate from an epithelial-to-mesenchymal transformation of the epicardial mesothelium, but the origin of the coronary endothelium is still obscure. We herein report that at least part of the population of the precursors of the coronary endothelium are epicardially-derived cells (EPDCs). We have performed an EPDC lineage study through retroviral and fluorescent labelling of the proepicardial and epicardial mesothelium of avian embryos. In all the experiments onlythe surface mesothelium was labelled after 3 h of reincubation. However, endothelial cells from subepicardial vessels were labelled after 24-48 h and endothelial cells of intramyocardial vessels were also labelled after 48-96 h of reincubation. In addition, the development of the coronary vessels was studied in quail-chick chimeras, obtaining results which also support a mesothelial origin for endothelial and smooth muscle cells. Finally, quail proepicardial explants cultured on Matrigel showed colocalization of cytokeratin and QH1 (mesothelial and endothelial markers, respectively) after 24 h. These results, taken together, suggest that EPDC show similar competence to that displayed by bipotential vascular progenitor cells [Yamashita et al., Nature 408: 92-96 (2000)] which are able to differentiate into endothelium or smooth muscle depending on their exposure to VEGF or PDGF-BB. It is conceivable that the earliest EPDC differentiate into endothelial cells in response to myocardially-secreted VEGF, while further EPDC would be recruited by the nascent capillaries via PDGFR-beta signalling, giving rise to mural cells.
authors.affiliation: Department of Cell Biology and Anatomy, Medical University of South Carolina, USA.
authors.forename: José-María
authors.initials: JM
authors.lastname: Pérez-Pomares
authors.forename: Rita
authors.initials: R
authors.lastname: Carmona
authors.forename: Mauricio
authors.initials: M
authors.lastname: González-Iriarte
authors.forename: Gerardo
authors.initials: G
authors.lastname: Atencia
authors.forename: Andy
authors.initials: A
authors.lastname: Wessels
authors.forename: Ramón
authors.initials: R
authors.lastname: Muñoz-Chápuli
mesh_terms: D000818:Animals; D000077214:Becaplermin; D002454:Cell Differentiation; D002642:Chick Embryo; D003094:Collagen / Q000494:pharmacology; D004338:Drug Combinations; D016228:Endothelial Growth Factors / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology* / Q000473:pathology; D005347:Fibroblasts / Q000378:metabolism; D006321:Heart / Q000196:embryology; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D007797:Laminin / Q000494:pharmacology; D008222:Lymphokines / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D009206:Myocardium / Q000166:cytology / Q000378:metabolism / Q000473:pathology*; D009924:Organ Culture Techniques; D010496:Pericardium / Q000166:cytology / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000378:metabolism; D011509:Proteoglycans / Q000494:pharmacology; D020574:Proto-Oncogene Proteins c-sis; D011784:Quail; D012190:Retroviridae / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
chemical_list: D004338:Drug Combinations; D016228:Endothelial Growth Factors; D036341:Intercellular Signaling Peptides and Proteins; D007797:Laminin; D008222:Lymphokines; D010982:Platelet-Derived Growth Factor; D011509:Proteoglycans; D020574:Proto-Oncogene Proteins c-sis; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; C059485:matrigel; D000077214:Becaplermin; D003094:Collagen