title: Developmental platelet endothelial cell adhesion molecule expression suggests multiple roles for a vascular adhesion molecule.
abstract: Platelet endothelial cell adhesion molecule (PECAM) is used extensively as a murine vascular marker. PECAM interactions have been implicated in both vasculogenesis and angiogenesis. To better understand the role of PECAM in mammalian development, PECAM expression was investigated during differentiation of murine embryonic stem (ES) cells and in early mouse embryos. Undifferentiated ES cells express PECAM, and as in vitro differentiation proceeds previously unidentified PECAM-positive cells that are distinct from vascular endothelial cells appear. PECAM expression is gradually restricted to endothelial cells and some hematopoietic cells of differentiated blood islands. In embryos, the preimplantation blastocyst contains PECAM-positive cells. PECAM expression is next documented in the postimplantation embryonic yolk sac, where clumps of mesodermal cells express PECAM before the development of mature blood islands. The patterns of PECAM expression suggest that undifferentiated cells, a prevascular cell type, and vascular endothelial cells express this marker during murine development. PECAM expression in blastocysts and by ES cells suggests that PECAM may function outside the vascular/hematopoietic lineage.
authors.affiliation: Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
authors.forename: S D
authors.initials: SD
authors.lastname: Redick
authors.forename: V L
authors.initials: VL
authors.lastname: Bautch
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000096:biosynthesis; D001755:Blastocyst / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D004622:Embryo, Mammalian / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism*; D007150:Immunohistochemistry; D016256:Lewis X Antigen / Q000378:metabolism; D051379:Mice; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000096:biosynthesis*; D012313:RNA / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000378:metabolism
chemical_list: D018952:Antigens, CD34; D016256:Lewis X Antigen; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D012313:RNA