Expression and function of laminin and integrins on adhesion/migration of primary culture cells derived from rat oral epithelium

Sugisawa M, Masaoka T, Enokiya Y, Muramatsu T, Hashimoto S, Yamada S, Shimono M. Expression and function of laminin and integrins on adhesion/migration of primary culture cells derived from rat oral epithelium. J Periodont Res 2010; 45: 284–291. © 2010 John Wiley & Sons A/S Background and Objective: It remains controversial whether or not the junctional epithelium cells that are directly attached to teeth migrate on the enamel surface, as those cells are able to adhere firmly to the enamel. The aim of this study was to investigate the expression patterns of laminin γ₂, integrin β₄ and integrin α₃, and to examine their potential function in cell migration. Material and Methods: Oral epithelium cells obtained from Sprague–Dawley rats were established in primary culture. We employed a wound‐healing assay to characterize the direction of cell extension at the start of cell migration, and observed different localizations of laminin and integrins using immunofluorescence. For functional analyses of integrins, we employed a phosphatidylinositol‐3‐kinase (PI3K) activator to promote integrin β₄ function and used P1B5 to inhibit integrin α₃ function, and we analyzed the percentage of re‐epithelialization as the migration function. Results: Marked accumulation of laminin γ₂ was detected in the peripheral cytoplasm of cells adjacent to the wound area, as shown by the results of the migration assay. Integrin β₄ was detected in the distal cell processes of actively migrating cells, while integrin α₃ was found in cell membranes of cells adjacent to the wound area. In the functional analyses, the percentage of re‐epithelialization was significantly lower in the PI3K‐activator group and in the P1B5‐treated group (2.5% and 7.2%, respectively) than in the control group (39.0%) (p < 0.01). Conclusion: The results suggest that laminin γ₂ is secreted as a foothold for cell migration, that integrin β₄ participates in cell adhesion and that integrin α₃ is involved in cell migration in the primary culture cells.