A Quantifiable In Vitro Model to Assess Effects of PAI-1 Gene Targeting on Epithelial Cell Motility

Gene “knockout” studies and analysis of physiologically relevant in vitro models have clarified basic mechanisms in the tissue response to injury (1 -5 ). Fundamental to this process is the genetic reprogramming required for conversion of normally sedentary cells to an actively motile, invasive phenotype (5 ,6 ). It is difficult, however, to identify important events among the diverse changes associated with the initiation and maintenance of migration or the acquisition of “plasticity” in a specific cell type in the intact animal. Thus, the development of in vitro approaches that closely mimic defined stages in epidermal wound repair facilitates discovery of the critical elements and provides an opportunity to probe the underlying molecular mechanisms.