Fig. 7

Histopathological evaluation of urothelium regeneration. H&E (a) and AE1/AE3 IHC (b) staining was used to assess the urothelial regeneration at 2, 3, and 4 weeks and 3 months after transplantation. In the 5% PAA-treated SIS only group, a discontinuous epidermal layer was observed on the luminal surface of the urethra 2 weeks after surgery, and the cellular layer increased over time. At 3 months, the luminal surface had formed an intact and multilayered urothelium. By contrast, complete epidermal cellular layers were formed at 2 weeks in the autologous USC-seeded 5% PAA-treated SIS group, and the urothelium continued to increase over 3 months but then did not change after 3 months. c Infiltration of inflammatory cells (arrow) and fibrosis (*) were observed in the 5% PAA-treated SIS only group. Scale bar = 200 μm. d Image analysis was used to calculate the ratio of the AE1/AE3-positive area to the total area at each time point in the two groups. *Significantly lower than in the autologous USC-seeded 5% PAA-treated SIS group at 2, 3, and 4 weeks after transplantation (P < 0.05). m months, USC urine-derived stem cell, w weeks