Dynamics of E-cadherin and γ-catenin complexes during dedifferentiation of polarized MDCK cells

Academic Article

Abstract

  • Background. E-cadherin mediated cell-cell adhesion ana hepatocyte growth factor (HGF) are important for renal epithelial morphogenesis. We previously showed that HGF dedifferentiates previously well polarized Madin-Darby canine kidney (MDCK) cell monolayers grown on filters. The regulation of E-cadherin during epithelial dedifferentiation is not known. We hypothesized that E- cadherin mediated cell-cell adhesion is modulated during HGF induced dedifferentiation of MDCK cell monolayers. Methods. We analyzed E- cadherin/γ-catenin interaction and distribution during epithelial dedifferentiation in vitro using a model of polarized MDCK cell monolayers treated with HGF. Results. Surface immunoprecipitation experiments showed that HGF increased the amount of cell surface E-cadherin associated with γ- catenin. Biochemical and morphological examination of the TX-100 solubility of junctional E-cadherin and γ-catenin in control and HGF treated cells showed an increase in solubility of only E-cadherin during loss of cell polarity. Metabolic labeling of control and HGF treated cells showed that HGF stimulated the synthetic rate of E-cadherin and γ-catenin molecules. Inulin flux across MDCK cell monolayers increases with HGF treatment. Conclusion. These data provide evidence for both the dissociation of E-cadherin molecules from the actin cytoskeleton and an increase in the total number of E- cadherin/γ-catenin complexes on the cell surface during HGF-induced dedifferentiation of polarized renal epithelium. These data support the hypothesis that E-cadherin function is inhibited by a mechanism of detachment from the actin based cytoskeleton during HGF induced dedifferentiation of polarized renal epithelia.
  • Published In

    Digital Object Identifier (doi)

    Author List

  • Balkovetz DF; Sambandam V
  • Start Page

  • 910
  • End Page

  • 921
  • Volume

  • 56
  • Issue

  • 3