Effects of cadmium chloride on the functional state of human intestinal cells

Toxic effects of cadmium chloride in concentration range from 1 to 300 μM on differentiated human intestinal epithelial Caco-2 cells after three hours of exposure were investigated. Processes of disorganization of the actin cytoskeleton associated with the toxic effects of cadmium were characterized by fluorescent microscopy. The cadmium-induced activation of cellular stress response processes (changes in the mRNA expression of caspase-3, heat-shock and oxidative stress genes) has been demonstrated. The study revealed dose-dependent changes in mRNA expression levels of proteins involved in the formation of adherens (E-Cadherin and p120 catenin) and tight intercellular junction contacts (Claudin 4 and ZO1). The time- and concentration-dependent trend of cell monolayer transepithelial resistance lowering, characterizing the loss of intercellular contacts density with prolongation of cell exposure cadmium chloride was estimated. Results indicates that proteins associated with tight and adhesion junctions are primary targets of cadmium. Amongst genes involved in cell junction formation, the genes encoding E-Cadherin and p120-catenin proved to be the most sensitive to cadmium influence.