Hepatocyte growth factor alters the polarity of Madin-Darby canine kidney cell monolayers

Hepatocyte growth factor (HGF) and E-cadherin are important for epithelial morphogenetic events. We examined the effects of HGF on E-cadherin localization and interaction with beta-catenin in polarized Madin-Darby canine kidney (MDCK) cell monolayers grown on filters. Surface biotinylation experiments showed that HGF increases apically accessible E-cadherin. Confocal immunofluorescence microscopy of HGF-treated cells showed localization of E-cadherin at membrane domains contacting the apical compartment and an increase in accessibility of apically applied antibodies to lateral E-cadherin below the tight junction. Coimmunoprecipitation of beta-catenin/E-cadherin complexes showed that the amount of E-cadherin associated with beta-catenin increased during the first 24 h of HGF treatment with a return to baseline values after 48 and 72 h. Metabolic labeling showed that HGF increased the synthetic rate of beta-catenin and the amount of newly synthesized E-cadherin associated with immunoprecipitated beta-catenin, with the peak effect occurring after 12 h of treatment and returning to baseline after 24 h. HGF treatment inhibited transcytosis of immunoglobulin A by the polymeric immunoglobulin receptor. We conclude that HGF treatment of polarized MDCK cells grown on filters decreases cell polarity and alters E-cadherin/beta-catenin interaction and synthesis.