Expressions of galectin-3, glutathione S-transferase A2 and peroxiredoxin-1 by nonylphenol-incubated Caco-2 cells and reduction in transepithelial electrical resistance by nonylphenol.

Nonylphenol, an estrogenic xenobiotic widely used in the manufacture of plastics and detergents, has been found in drinking water and may therefore enter the body through the oral route. Thus, intestinal cells lining the alimentary tract serve as the body's first line of defense against this compound. In this study, the effects of nonylphenol on the human intestinal cell line Caco-2 were determined using transepithelial electrical resistance (TEER) measurement and proteomics. Results show that 10 microM nonylphenol can disrupt the tight-junction permeability of Caco-2 cells in approximately 15 min. Incubating the cells with 1 or 10 microM nonylphenol for 6 days resulted in the enhanced expressions of galectin-3 (approximately 4-fold vs. control with 1 microM; 2-fold with 10 microM), glutathione S-transferase A2 (approximately 8-fold with 1 microM; 5-fold with 10 microM) and peroxiredoxin-1 (approximately 6-fold with 1 microM; 4-fold with 10 microM). These expressions may represent a possible consortium of mechanisms by which the cells protect themselves against nonylphenol-induced stresses. To the best of our knowledge, this is the first study on the effects of nonylphenol on Caco-2 cells.