The Expression of Adhesion Molecules and Proliferative Activity in the Human Gingival Epithelium

Abstract

The aims of this study were to investigate the proliferative activity and the localization of adhesion molecules in human healthy and inflamed portions of gingiva. Gingival biopsies were taken under informed consent from 33 patients undergoing gingivectomy at the Dental Hospital of Iwate Medical University. Adhesion molecules such as E-cadherin (of adherens junction-related molecules), desmoglein (of desmosomal cadherins), integrin α6 and integrin, β4 (of hemidesmosome-related molecules) were studied immunohistochemically to analyze the patterns of expression in the gingival epithelia. Desmoglein was detected intercellularly in the spinous layer of the lining epithelia, but not in the junctional epithelium (JE). Integrin α6 was confined to the basement membranes facing the connective tissue of all parts of the gingival epithelia. Integrin β4 was found in the basal layer of the epithelia, and it was markedly found in all layers of the JE. The expression patterns of adhesion molecules in the pocket epithelium (PE) were similar to those in the JE. The proliferative activity was analyzed by the bromodeoxyuridine (BrdU) labeling method and immunohistochemical staining for Ki-67. BrdU-positive cells were found in the basal layer of the sulcular (SE) and oral epithelia (OE), but not in the JE, and were particularly localized in the suprabasal layer at the bottom of the SE. Meanwhile, proliferative activity was found in the PE with the progression of ueriodontitis.