Redistribution of fodrin in an in vitro wound healing model of the corneal epithelium.
We previously observed the redistribution of a membrane skeletal protein, fodrin, after wounding in the corneal epithelium in vivo. In this study, we made an in vitro wound healing model using cultured corneal epithelial cells to investigate the redistribution mechanism of fodrin in the corneal epithelial cells. The distributional change of fodrin from the plasmalemma to the cytoplasm was observed soon after wounding by indirect immunofluorescence microscopy and laser scanning confocal microscopy. A similar change was caused by treating intact cells with phorbol-12-myristate-13-acetate (PMA), but not with calcium ionophore, A23187. The redistribution occurred even in cells pretreated with 1,2-bis(O-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetomethyl ester (BAPTA-AM) before wounding. The redistribution caused by wounding or by PMA was inhibited by pretreating the cells with protein kinase C inhibitors, H-7 or calphostin C. Moreover, the reagents were found to slow down the migration of corneal epithelial cells after wounding. These results suggest that the redistribution of fodrin in the wounded corneal epithelium is caused through the activation of protein kinase C and might be related to the ensuing cell migration.