Remodeling of Buccal Mucosa by Bladder Microenvironment

Objectives

The optimal cell source for bladder mucosa reconstruction is in question. This study explored the feasibility of phenotype transformation of oral mucosa towards bladder urothelium by transplanting the oral mucosa into bladder local microenvironment.

Methods

Porcine oral mucosa grafts were transplanted into autologous bladder mucosa defects, and the specific marker expressions of both oral epithelium and bladder urothelium were examined by immunohistochemistry and RT-PCR at 3, 6, and 12 months to detect a potential phenotype transformation.

Results

The grafts could retain the phenotype and structure of oral mucosa within 3 months with positive expression of cytokeratin 14 (CK 14, a specific marker of oral epithelium) and negative expression of uroplakin II (UPII, a urothelium-specific marker). However, after 6 months of transplantation, the grafts expressed UPII at both protein and mRNA levels and the phenotype persisted at 12 months postsurgery. All the grafts continuously retained the positive expression of CK 14 at all time points.

Conclusions

These findings, for the first time, revealed the transdifferential potential of oral keratinocytes toward urothelial cells and the important role of bladder local microenvironment for remodeling oral mucosa epithelium. These results support the hypothesis that oral keratinocytes can serve as a potential cell source for reconstructing bladder mucosa.