In vitro cytokeratin expression profiling of human oral mucosa substitutes developed by tissue engineering

In this work we performed a study of cytokeratin (CK) expression profiling on human artificial oral mucosa developed in vitro by tissue engineering at different stages of maturation (from immature to well-developed stages) at the protein and mRNA levels. Human artificial oral mucosa was generated in the laboratory using fibrin-agarose biomaterials. As controls, we used human native normal oral mucosa and embryonic oral tissues. Our results demonstrated that human embryonic oral tissues tended to express CK8 and CK19. In contrast, monolayered bioengineered oral mucosa did not show any CK expression by immunohistochemistry, whereas bilayered and multilayered artificial oral mucosa showed several markers of stratified epithelia, but did not express CK10. These results suggest that the CK expression pattern is strongly dependent on the maturation state of the artificial tissues and that the CK expression profile of our model of artificial oral mucosa was partially similar to that of the non-keratinized human adult oral mucosa. However, the expression of CK8 by the artificial oral mucosa suggests that these samples correspond to an early stage of development while kept in vitro.