Fig. 4. UUO upregulated IL-33 expression in the hyperplasic intrarenal urothelium.

a Immunofluorescence staining of IL-33 (red), KRT5 (green), and nuclei with DAPI (blue) in kidney tissues from C57BL/6 mice with UUO surgery. b Co-localization of IL-33 (red) in KRT5+ (green) urothelial cells in the UPJ but not in the urothelium within the fornix. IL-33 is markedly expressed in the hyperplasic urothelium in the obstructed kidney. c Quantification of IL-33+ cells among KRT5 cells in the fornix and UPJ of control and UUO kidneys; *p < 0.05. d IL-33 is not expressed in UPK3a+ superficial cells