ABSTRACT
The airway epithelium provides much more than a barrier between the host and environment. Epithelial cells are important sources of mediators and play important roles in the pathogenesis of a variety of lung diseases including, asthma and chronic obstructive pulmonary disease (COPD). In this context, epithelial cells are capable of participating in inflammatory cytokine cascades and matrix remodeling. Recruitment, proliferation, and differentiation of epithelial cells are key in epithelial repair following injury. Conversely, persistent damage or metaplasia of the epithelium can contribute to impaired airway function. While less well studied, damage of the alveolar epithelium may play a role in emphysema.
