Hair follicle stem cells can be driven into a urothelial-like phenotype: an experimental study

The aim of this study was to show that conditioned medium might induce transdifferentiation of hair follicle stem cells into urothelial-like cells. Several conditioned media and culture conditions (skeletal muscle cell conditioned medium, smooth muscle cell conditioned medium, fibroblast conditioned medium, transforming growth factor-conditioned medium, urothelial cell conditioned medium, and co-culture of hair follicle stem cells and urothelial cells) were used. The hair follicle stem cells phenotype from rat whisker hair follicles was checked by using flow cytometry and immunofluorescence. Cytokeratins 7, 8, 15 and 18 were used as markers. Urothelial cell conditioned medium increased the expression of urothelial markers (cytokeratin 7, cytokeratin 8, cytokeratin 18), whereas it decreased a hair follicle stem cells marker (cytokeratin 15) after 2 weeks of culture. This process depended on the time of cultivation. This medium was able to sustain the epithelial phenotype of the culture. Other media including a co-culture system failed to induce similar changes. Smooth muscle conditioned medium resulted in a loss of cells in culture. Hair follicle stem cells are capable of differentiating into urothelial-like cells in vitro when exposed to a bladder-specific microenvironment.