title: Restricted and coordinated expression of beta3-integrin and bone sialoprotein during cultured osteoblast differentiation.
abstract: In this study, the expression of beta3-integrin was examined in relationship to the restricted expression of bone sialoprotein (BSP). Immunohistochemical analysis indicated that the alpha(v)beta3-integrin was coincident and proximal to BSP expression in the fetal mandible bovine osteoblast culture model. Alpha(v)beta3-integrin expression was expressed predominantly in a region proximal to, but not including, the substrate adherent cells. In comparison, the alpha5beta1-integrin was expressed in a generalized pattern throughout the culture layers in a coordinated fashion to fibronectin. The temporal expression of beta1- and beta3-integrin was evaluated using RT-PCR and southern blot analysis. Unlike the generalized expression of beta1-integrin, beta3-integrin was restricted to days 3 and 5 of the culture period. The previous demonstration of similar restriction of BSP expression and the present colocalization of BSP suggests the potential coordinated expression of a specific extracellular matrix ligand with a select integrin. Beta3-integrin/BSP adhesion-mediated signaling may play a significant role in the process of osteoblast morphodifferentiation.
authors.affiliation: Dental Research Center and Department of Prosthodontics, The University of North Carolina School of Dentistry, Chapel Hill 27599-7450, USA.
authors.forename: G B
authors.initials: GB
authors.lastname: Schneider
authors.forename: S W
authors.initials: SW
authors.lastname: Whitson
authors.forename: L F
authors.initials: LF
authors.lastname: Cooper
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis*; D015139:Blotting, Southern; D002417:Cattle; D002448:Cell Adhesion / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D005353:Fibronectins / Q000032:analysis; D007150:Immunohistochemistry; D039661:Integrin beta3; D058574:Integrin-Binding Sialoprotein; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D010980:Platelet Membrane Glycoproteins / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis; D019030:Receptors, Vitronectin / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012795:Sialoglycoproteins / Q000096:biosynthesis*
chemical_list: D015703:Antigens, CD; D005353:Fibronectins; D039661:Integrin beta3; D058574:Integrin-Binding Sialoprotein; D010980:Platelet Membrane Glycoproteins; D012333:RNA, Messenger; D019030:Receptors, Vitronectin; D012795:Sialoglycoproteins