Early Epithelial Differentiation Associated Protein (EEDA)

EEDA is uniquely associated with an early stage of stratified epithelial differentiation. In epidermis, esophageal epithelium, and tongue epithelium, EEDA mRNA, and antigen was abundant in suprabasal cells, but was barely detectable in more differentiated cells. EEDA was expressed in basal corneal epithelial cells that are out of the stem cell compartment, as well as the suprabasal corneal epithelial cells. The strongest EEDA expression occurred in suprabasal precortical cells of mouse, bovine, and human anagen follicles. Interestingly, EEDA expression is turned off when epithelia were perturbed by wounding and by cultivation under both low and high Ca2+ conditions. EEDA is involved in the early stages of normal epithelial differentiation, and that EEDA is important for the "normal" differentiation pathway in a wide range of stratified epithelia.