title: Differential expression and localization of connexins 26 and 43 in the rat gingival epithelium.
abstract: We investigated the expression and localization of connexins (CX) 26 and 43 in the rat gingival epithelium. RT-PCR analysis revealed CX26 gene expression in both the upper and lower layers of the gingival epithelium and in the total epithelial layer, whereas CX43 gene expression was limited to the lower layer and the total epithelial layer. Immunoreactivity for CX43 was observed in the membranes of adjacent cells from the basal layer to the middle of the prickle cell layer, while immunoreactivity for CX26 was observed in the granular cell layer and lower part of the squamous cell layer. Merged images revealed the co-localization of CX26 and CX43 in the middle of the prickle cell layer. By immuno-electron microscopy, gap junctions appeared curved, hemi-circular, or annular within the cytoplasm, and gold particles indicating the presence of CX43 were localized at the outer edges of these cytoplasmic formations. These results suggest that CX43 is associated with the regulation of cell proliferation and that increased CX26 expression is associated with differentiation of keratinocytes. Thus, degradation of CX43 is considered to play an essential role in differentiation of the rat gingival epithelium.
authors.affiliation: Oral Health Science Center HRC7, Tokyo Dental College, Chiba, Japan. tmuramat@tdc.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Muramatsu
authors.forename: Tomoko
authors.initials: T
authors.lastname: Uekusa
authors.forename: Takayasu
authors.initials: T
authors.lastname: Masaoka
authors.forename: Masato
authors.initials: M
authors.lastname: Saitoh
authors.forename: Sadamitsu
authors.initials: S
authors.lastname: Hashimoto
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Abiko
authors.forename: Han-Sung
authors.initials: HS
authors.lastname: Jung
authors.forename: Masaki
authors.initials: M
authors.lastname: Shimono
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D049109:Cell Proliferation; D000072259:Connexin 26; D018031:Connexin 43 / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D017630:Connexins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D017629:Gap Junctions / Q000378:metabolism / Q000648:ultrastructure; D005881:Gingiva / Q000378:metabolism*; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism; D008297:Male; D016253:Microscopy, Immunoelectron; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D018031:Connexin 43; D017630:Connexins; C000607044:Gjb2 protein, rat; D000072259:Connexin 26