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Differential localization of laminin γ 2 and integrin β 4 in primary cultures of the rat gingival epithelium
Author(s) -
Tanno Michie,
Hashimoto Sadamitsu,
Muramatsu Takashi,
Matsuki Miwako,
Yamada Satoru,
Shimono Masaki
Publication year - 2006
Publication title -
journal of periodontal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.31
H-Index - 83
eISSN - 1600-0765
pISSN - 0022-3484
DOI - 10.1111/j.1600-0765.2005.00831.x
Subject(s) - laminin , epithelium , junctional epithelium , integrin , pathology , chemistry , biology , microbiology and biotechnology , medicine , biochemistry , extracellular matrix , cell
Objectives: The aim of this study was to investigate the differential immunolocalization of laminin γ 2 and integrin β 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 γ 2 and integrin β 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 γ 2 and integrin β 4 were detected by Western blot analysis in the gingival epithelium. Immunolocalization of laminin γ 2 was distinct in the cytoplasm to form one or two irregular rings in gingival epithelial cells. By contrast, integrin β 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 γ 2 was recognized as large foci in the most inner portion just above the basal plasma membrane. Integrin β 4 existed in the area where F‐actin was labeled surrounding the membrane. Immuno‐electron microscopy showed that 10nm colloidal gold particles indicating laminin γ 2 were mainly localized at the extracellular portion and in the peripheral cytoplasm, whereas integrin β 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 γ 2 and integrin β 4 may be produced by the epithelium, and irregular rings of laminin γ 2 are formed in areas where gingival cells adhere to the extracellular matrix.