Generation of Urothelial Cells from Mouse-Induced Pluripotent Stem Cells.

Background and objectives: The search for a suitable alternative for urethral defect is a challenge in the field of urethral tissue engineering. Induced pluripotent stem cells (iPSCs) possess multipotential for differentiation. The in vitro derivation of urothelial cells from mouse-iPSCs (miPSCs) has thus far not been reported. The purpose of this study was to establish an efficient and robust differentiation protocol for the differentiation of miPSCs into urothelial cells.

Methods and results: Our protocol made the visualization of differentiation processes of a 2-step approach possible. We firstly induced miPSCs into posterior definitive endoderm (DE) with glycogen synthase kinase-3β (GSK3β) inhibitor and Activin A. We investigated the optimal conditions for DE differentiation with GSK3β inhibitor treatment by varying the treatment time and concentration. Differentiation into urothelial cells, was directed with all-trans retinoic acid (ATRA) and recombinant mouse fibroblast growth factor-10 (FGF-10). Specific markers expressed at each stage of differentiation were validated by flow cytometry, quantitative real-time polymerase chain reaction (qRT-PCR) assay, immunofluorescence staining, and western blotting Assay. The miPSC-derived urothelial cells were successfully in expressed urothelial cell marker genes, proteins, and normal microscopic architecture.

Conclusions: We built a model of directed differentiation of miPSCs into urothelial cells, which may provide the evidence for a regenerative potential of miPSCs in preclinical animal studies.