A pattern of epidermal cell migration during wound healing.

Epidermal repair during wound healing is under investigation at both the light and electron microscopic levels. Suction-induced subepidermal blisters have been employed to produce two complementary model wound healing systems. These two model systems are: (a) intact subepidermal blisters, and (b) opened subepidermal blisters (the blister roof was removed immediately after induction, leaving an open wound). From these studies a pattern of movement for epidermal cells in wound healing is proposed. This pattern of movement is the same for both model systems. Epidermal cells appear to move by rolling or sliding over one another. Fine fibers oriented in the cortical cytoplasm may play an important role in the movement of these epidermal cells. Also instrumental in mediating this movement are intercellular junctions (desmosomes) and a firm attachment to a substrate through hemidesmosomes. In the intact subepidermal blisters hemidesmosomal attachment is made to a continuous and homogeneous substrate, the retained basal lamina. In the opened subepidermal blisters contact of epidermal cells is made to a discontinuous substrate composed of sporadic areas of fibrin and underlying mesenchymal cells.