Role of matrix metalloproteinases in epithelial migration.

In response to injury, epithelial cells migrate across the denuded tissue to rapidly close the wound and restore barrier, thereby preventing the entry of pathogens and leakage of fluids. Efficient, proper migration requires a range of processes, acting both inside and out of the cell. Among the extracellular responses is the expression of various matrix metalloproteinases (MMPs). Though long thought to ease cell migration simply by breaking down matrix barriers, findings from various models demonstrate that MMPs facilitate (and sometimes repress) cell movement by other means, such as affecting the state of cell-matrix interactions or proliferation. In this Prospect, we review some key data indicting how specific MMPs function via their activity as proteinases to control closure of epithelial wounds. (c) 2009 Wiley-Liss, Inc.