Intermediate filaments of epithelial cells generally consist of specific combinations of
keratins. However, cultured epithelial cells from certain tissues and some epithelial
tumors have been shown also to express
vimentin. In the present study, the expression of
vimentin by epithelial cells in healing corneal
wounds (partial thickness
penetrating wounds) and in tissue culture was analyzed. Both immunohistochemical and immunotransblot analyses indicated that although
vimentin was not detected in the normal rabbit corneal epithelium in vivo, cultured rabbit corneal epithelial cells co-express
keratins and
vimentin. At 1 day post-wounding,
vimentin was not detectable in the epithelial cells that had covered the denuded stroma. However, at 2 days postwounding, the epithelium at the base of the epithelial plug immunoreacted with both anti-
vimentin and antikeratin
monoclonal antibodies. Immunotransblot analyses of the extracts of the epithelial plugs confirmed the presence of
vimentin (Mr = 58k). The 58k band was not detected in the extract of normal rabbit corneal epithelium. At day/5,
vimentin was no longer detectable in the epithelium. This study demonstrated that corneal epithelial cells transiently co-express
vimentin and
keratins in vivo during wound healing and in tissue culture. The time-course of the transient expression of
vimentin suggests that the
vimentin expression in the epithelial cells during healing is not linked to cell proliferation or to the centripetal migration of the epithelium during early stages (first 24 h) of healing, but may be linked to cell-matrix interactions or the migration of basal cells in the upward direction at the following stage of healing.