UBC Theses and Dissertations
Expression of αvβ6 integrin in the junctional epithelium Garcia Fulle, Maria Isabel
Cell-cell binding and cell-extracellular matrix adhesion is mediated by cell surface receptors known as integrins, which play important roles during wound healing. Junctional epithelium (JE) that links gingiva to tooth enamel mimics wound epithelium. The αvβ6 integrin is an epithelial integrin that is not normally expressed by oral gingival epithelium but is induced during wound healing, and has also been shown to be expressed in squamous cell carcinomas and in leukoplakia specimens. Furthermore, αvβ6 integrin can bind and activate transforming growth factor-β (TGF-β), suggesting a central role for the integrin in this unique epithelium. Using human gingival specimens from extracted teeth and human gingival specimens attached to decalcified teeth, the presence of JE was confirmed using simple epithelia tissue markers (cytokeratin-19 and laminin-5). The presence of αvβ6 integrin in the JE and some of its putative ligands (such as tenascin, fibronectin and TGF-β) was confirmed using immunohistochemical labelling. Paraffin sections of wild-type (FVB), β6integrin-overexpressing (B6F1) and P6integrin-knock-out mice (β6-/-) were stained with hematoxylin and eosin and observed under the light microscope to analyze the morphology of the JE. Interestingly, the analysis of the β6-/- sections showed striking alterations in the morphology and cellular organization of the JE. The findings of this study suggest that αvβ6 integrin is constitutively expressed in the JE, in which it could function as an immunoregulator via activation of TGF-β1.
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