title: Stem cell antigen-1 expression in the pulmonary vascular endothelium.
abstract: Although the function of the cell surface protein stem cell antigen-1 (Sca-1) has not been identified, expression of this molecule is a characteristic of bone marrow-derived hematopoietic stem cell populations. Expression of Sca-1, however, is not restricted to hematopoietic tissue. By RT-PCR and Western analysis, we found that Sca-1 is expressed in the adult mouse lung. Sca-1 immunohistochemistry revealed a linear staining pattern on the endothelial surface of large and small pulmonary arteries and veins and alveolar capillaries. Expression of Sca-1 in the pulmonary endothelium was confirmed by dual fluorescent microscopy on lung sections and by fluorescence-activated cell sorting analysis of digested lung tissue; each of these methods showed colocalization with the endothelial marker platelet/endothelial cell adhesion molecule-1. In the kidney, Sca-1 expression was also noted in large vessels, but, in contrast to the lung, was not observed in capillaries. Overall, our data indicate that Sca-1 expression helps define the surface phenotype of endothelial cells throughout the pulmonary vasculature.
authors.affiliation: The Pulmonary Center, Boston University School of Medicine, Boston, Massachusetts 02118, USA. dkotton@lung.bumc.bu.edu
authors.forename: Darrell N
authors.initials: DN
authors.lastname: Kotton
authors.forename: Ross S
authors.initials: RS
authors.lastname: Summer
authors.forename: Xi
authors.initials: X
authors.lastname: Sun
authors.forename: Bei Yang
authors.initials: BY
authors.lastname: Ma
authors.forename: Alan
authors.initials: A
authors.lastname: Fine
mesh_terms: D000818:Animals; D000950:Antigens, Ly / Q000032:analysis / Q000235:genetics*; D015415:Biomarkers; D004730:Endothelium, Vascular / Q000737:chemistry / Q000502:physiology*; D005434:Flow Cytometry; D015870:Gene Expression / Q000502:physiology; D007150:Immunohistochemistry; D007668:Kidney / Q000098:blood supply / Q000737:chemistry; D008168:Lung / Q000098:blood supply*; D008565:Membrane Proteins / Q000032:analysis / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D011651:Pulmonary Artery / Q000737:chemistry / Q000502:physiology; D011667:Pulmonary Veins / Q000737:chemistry / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D000950:Antigens, Ly; D015415:Biomarkers; C074650:Ly6a protein, mouse; D008565:Membrane Proteins; D012333:RNA, Messenger