Immunolocalization of laminin and integrin in regenerating junctional epithelium of mice after gingivectomy

Abstract

Masaoka T, Hashimoto S, Kinumatsu T, Muramatsu T, Jung H-S, Yamada S, Shimono M. Immunolocalization of laminin and integrin in regenerating junctional epithelium of mice after gingivectomy. J Periodont Res 2009; 44: 489-495. © 2008 The Authors. Journal compilation© 2008 Blackwell MunksgaardBackground and Objective: The expression patterns of adhesive proteins and extracellular matrix proteins in regenerating gingival epithelium after gingivectomy are unknown. The aim of this study was to examine the expression of laminin 1, laminin γ2 (a specific component of laminin 5), integrin β4 and integrin α3 in the regenerating gingival epithelium in order to understand the mechanism of wound healing during reconstitution of the sulcular environment. Material and Methods: The palatal gingivae of the maxillary molars of Institute of Cancer Research mice were excised, and the regenerating tissues were examined 1, 3, 5, 7 and 14 days later. Fresh, non-fixed and non-decalcified frozen sections were prepared and stained using immunofluorescence. Results: At 1 day post-surgery, intense expression of laminin γ2, integrin β4 and integrin α3 was distinct in the frontal margin of the regenerating oral epithelium. Laminin γ2 was diffusely detected on the root surface and in connective tissues beneath the regenerating oral epithelium at 3 and 5 days. At 7 days, laminin γ2 was intermittently recognizable in the internal basal lamina (IBL) close to tooth-facing cells, while laminin γ2, integrin β4 and integrin α3 were observed in the IBL and in the external basal lamina (EBL) of the regenerating junctional epithelium at 14 days. Conclusion: These results suggest that secretion of laminin 5 in the connective tissue may induce epithelial cell migration, and that binding of laminin 5 to integrin α6β4 and integrin α3β1 in the IBL may provoke cell adhesion and migration of cells facing the tooth on the enamel surface of the regenerating junctional epithelium. © 2008 Blackwell Munksgaard.