Motogenic effect of recombinant HGF on airway epithelial cells during the in vitro wound repair of the respiratory epithelium

Cell migration is the earliest mechanism involved in the wound repair proce ss of the respiratory epithelium and could be potentially enhanced by growt h factors. In the present work, we investigated the localisation of the hep atocyte growth factor (HGF) receptor (c-Met) during wound repair and evalua ted the effect of recombinant HGF (rHGF) on cell migration by using an in v itro model of airway epithelial wound repair. By using immunohistochemical methods, we observed that the immunoreactivity of the c-Met proto-oncogene was increased in epithelial cells engaged in the process of tissue repair. The incubation of wounded cultures with increasing concentrations of rHGF ( 0.2, 2, 20, and 200 ng/ml) induced a significant (P < 0.02) dose-dependent effect on the wound repair index, with a maximum effect produced at 20 ng/m l (+31.3%). The cell migration speed reached 50.2 <mu>m/h at this concentra tion, compared to 20.4 mum/h in the absence of rHGF. No significant effect on cell proliferation was observed in the repairing area in the presence of rHGF. These results suggest that rHGF is able to improve the wound repair process of the airway epithelium by increasing cell migration. J. Cell. Phy siol. 185:447-453, 2000. (C) 2000 Wiley-Liss, Inc.