UBC Theses and Dissertations
Epithelial cell integrin phenotype in drug-induced gingival overgrowth tissue Walsh, Priscilla M.
Gingival overgrowth can be an unpleasant side effect of the commonly prescribed medications nifedipine and cyclosporin. Integrins are transmembrane glycoproteins that mediate cell-to-cell and cell-to-extracellular matrix cell adhesion events. The aim of this study was to characterize epithelial cell integrin phenotype in drug-induced gingival overgrowth tissue. Human gingival biopsies of patients taking nifedipine, cyclosporin, or a combination of both medications were used. Integrins and their ligands were localized in frozen sections using immunohistochemistry. Comparisons between integrin expression in normal and the drug-induced gingival tissue were made. The drug-induced gingival overgrowth tissue exhibited an increase in suprabasal expression of integrins αvβ1, α5β1, and αvβ6 which is similar to the integrin expression during wound healing. The integrin αvβ6 was expressed, however, with similar frequency in both the control and the drug-induced gingival overgrowth groups. Fibronectin, a possible ligand for the α5β1 and αvβ6 integrins, was not only expressed within the connective tissue of all groups, but was also expressed around some of the basal keratinocytes of the control, nifedipine-, and cyclosporin-induced gingival overgrowth groups. No relationship between inflammation and integrin expression could be identified. The results suggest that the epithelium of drug-induced gingival overgrowth tissue exhibit certain changes in its integrin repetoire. This upregulation of certain integrins, which is consistent to one seen during wound healing, could result in controlling the formation of the connective tissue.
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