Although cadmium inhalation affects lung function, no study
has addressed whether or not cadmium directly affects the
CFTR ion channel expressed by airway epithelial cells.
Because CFTR has to be present at the plasma membrane
and functional to exert its role as a key regulator in fluid
homeostasis in the airway, we wanted to investigate whether
cadmium would alter CFTR expression and function. Our
results indicate that cadmium, at doses that do not induce cell
death, decreases the expression and subsequent activity of
CFTR in various epithelial cell lines and primary cells as
well asin vivo in mice. This effect is because of increase of
CFTR ubiquitination/degradation. Interestingly, the antioxidant
a-tocopherol (vitamin E) prevented the cadmium-induced
inhibition of CFTR in bronchial epithelial cells and primary
human airway epithelial cells (HAEC).