Critical Reviews in Oral Biology & Medicine, Vol 1, 167-190, Copyright © 1990 by International & American Associations for Dental Research
New approaches and concepts in the study of differentiation of oral epithelia
B. A. Dale, J. Salonen and A. H. Jones
Department of Oral Biology, University of Washington, Seattle 98195.
Epithelial structural proteins, the keratins and keratin-associated
proteins, are useful as markers of differentiation because their expression
is both region-specific and differentiation-specific. In general, basal
cells in all stratified oral epithelia express similar keratins, while the
suprabasal cells express a specific set of markers indicating commitment to
a distinct program of differentiation. Critical factors in the regulation
of epithelial protein expression are now under investigation. The promoter
regions of keratin genes are being characterized to determine what
sequences within the genes are responsible for differential expression. One
important extracellular factor that influences epithelial protein
expression is retinol (vitamin A), which exerts its effects via a group of
nuclear receptor proteins that may also be expressed in a region-specific
manner. These molecular biological approaches enhance our understanding of
the mechanisms regulating differentiation of oral epithelia and its
regional complexity.
