Low levels of cadmium chloride alter the immunoprecipitation of corneal cadherin-complex proteins

Abstract.

The effect of cadmium chloride on the immunoprecipitation of cadherin and the associated adherens junctional proteins, α- and β-catenin, was examined in isolated bullfrog (Rana catesbeiana) corneas utilizing Western blot and enhanced chemoluminescent techniques. Application of either 1.0 µM or 75.0 µM CdCl₂ to the corneal endothelium for 2 h markedly decreased the immunoprecipitation of cadherins as compared to paired control corneas. Immunoprecipitation of α-catenin was increased in response to both doses of CdCl₂, while the immunoprecipitation of β-catenin was little changed by either cadmium dose. There is accumulating evidence that cadmium may increase epithelial paracellular permeability by interfering with cadherin complex activity at intercellular junctions. The present study suggests that inorganic cadmium in low micromolar concentrations may decrease the integrity of the corneal endothelium, at least in part through a similar mechanism involving disruption of junctional cadherin complex function.