Collagen 17A1 in the Urothelium Regulates Epithelial Cell Integrity and Local Immunologic Responses in Obstructive Uropathy

Collagen 17A1 (COL17A1), an epidermal hemidesmosome component, is ectopically induced in the urothelium of mouse and human renal pelvis (RP) in parallel with urinary tract-associated lymphoid structure development. Here, we found that COL17A1 was induced in obstructive uropathy-prone ureter of humans and cats. To ascertain its function, murine urinary organs with unilateral ureteral obstruction (UUO) were analyzed during 1 week after surgery. One day after UUO, COL17A1 expression increased in urothelial cells of RP and ureter, and was positively correlated with renal tubulointerstitial lesions. A portion of RP where the smooth muscle layer from the ureter was interrupted was sensitive to urothelium deciduation and COL17A1 induction, showing urine leaked from the RP lumen into the parenchyma. After urine stimulation, cultured immune cells expressed Cxcl2, also up-regulated in CD11b