ALTERED EXPRESSION OF EPITHELIAL-CELL SURFACE GLYCOCONJUGATES AND INTERMEDIATE FILAMENTS AT THE MARGINS OF MUCOSAL WOUNDS

Alterations in cell to cell adhesion are necessary to enable the type of cell movements that are associated with epithelial wound healing an d malignant invasion. Several studies of transformed cells have relate d epithelial cell movement to changes in the cell surface expression o f the carbohydrate structures represented by the ABO blood group antig ens and, in particular, by Lewis antigens and their biosynthetic precu rsors. To study further the relationship between cell surface carbohyd rates and keratinocyte cell movement, experimental wounds were created in human oral mucosa and examined by immunohistochemical methods for their expression of selected cytokeratins (K5, K16, K19), basement mem brane components (laminin alpha 5 and gamma 2-chains, BP180, collagen IV and collagen VII), and blood group antigen precursor structures Le( x), sialosyl-Le(x), Le(y), H antigen, N-acetyllactosamine, and sialosy l-T antigen. The changes induced by wounding in the expression of coll agen IV, laminin gamma 2-chain (laminin-5), and laminin alpha 5-chain were similar to those found in skin wounds and served to define the re gion of epithelial movement. This region was found to show a marked in crease in staining for both Lewis antigen Y (Le(y)) and H blood group antigen, and decreased staining of Le(x), thus indicating an upregulat ion in wounded epithelium of the fucosyltransferases responsible for t he synthesis of the H antigen. The changes in carbohydrate expression extended beyond the wound margin into the nonwounded epithelium, a pat tern of expression similar to K16, which was also strongly upregulated in both the outgrowth and the adjacent non-wounded epithelium. These findings provide further support for an influence of such carbohydrate structures on the migratory behavior of epithelial cells.