title: Differential localization of laminin gamma and integrin beta in primary cultures of the rat gingival epithelium.
abstract: OBJECTIVE
  The aim of this study was to investigate the differential immunolocalization of laminin gamma(2) and integrin beta(4) in primary cultures of the rat gingival epithelium.
  
  
  METHODS
  The gingival epithelium was obtained from Sprague-Dawley rats and was cultured in serum-free keratinocyte growth medium (DK-SFM). Western blotting analysis, immunofluorescence, confocal laser scanning microscopy (CLSM), and immuno-gold labeling for laminin gamma(2) and integrin beta(4) were employed. CLSM images for laminin and integrin were analyzed in horizontal (x-y axis) and in vertical (x-z axis) sections.
  
  
  RESULTS
  Both laminin gamma(2) and integrin beta(4) were detected by Western blot analysis in the gingival epithelium. Immunolocalization of laminin gamma(2) was distinct in the cytoplasm to form one or two irregular rings in gingival epithelial cells. By contrast, integrin beta(4) was localized diffusely in the cytoplasm. F-actin (indicating actin filaments) was clearly discernible at the periphery of the cytoplasm to form a cellular fringe. In x-z axis images obtained by CLSM, laminin gamma(2) was recognized as large foci in the most inner portion just above the basal plasma membrane. Integrin beta(4) existed in the area where F-actin was labeled surrounding the membrane. Immuno-electron microscopy showed that 10nm colloidal gold particles indicating laminin gamma(2) were mainly localized at the extracellular portion and in the peripheral cytoplasm, whereas integrin beta(4) was distributed in the cytoplasm close to the basal plasma membrane but not in extracellular regions.
  
  
  CONCLUSIONS
  In primary cultures of the rat gingival epithelium, both laminin gamma(2) and integrin beta(4) may be produced by the epithelium, and irregular rings of laminin gamma(2) are formed in areas where gingival cells adhere to the extracellular matrix.
authors.affiliation: Department of Periodontics, Tokyo Dental College, Chiba, Japan.
authors.forename: Michie
authors.initials: M
authors.lastname: Tanno
authors.forename: Sadamitsu
authors.initials: S
authors.lastname: Hashimoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Muramatsu
authors.forename: Miwako
authors.initials: M
authors.lastname: Matsuki
authors.forename: Satoru
authors.initials: S
authors.lastname: Yamada
authors.forename: Masaki
authors.initials: M
authors.lastname: Shimono
mesh_terms: D000199:Actins / Q000032:analysis; D000818:Animals; D015153:Blotting, Western; D002462:Cell Membrane / Q000648:ultrastructure; D002478:Cells, Cultured; D003593:Cytoplasm / Q000648:ultrastructure; D004847:Epithelial Cells / Q000166:cytology; D005109:Extracellular Matrix / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D005881:Gingiva / Q000166:cytology*; D007150:Immunohistochemistry; D039663:Integrin beta4 / Q000032:analysis*; D007797:Laminin / Q000032:analysis*; D018613:Microscopy, Confocal; D016253:Microscopy, Immunoelectron; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000199:Actins; D039663:Integrin beta4; D007797:Laminin