Unilateral Ureteral Obstruction

The surgical procedure was performed as previously described (Asada et al., 2011). Briefly, 6–12-week-old mice (acquired from the Model Animal Research Center, Nanjing University, China) were anesthetized and a mid-abdominal incision was made to expose the left ureter, after which a unilateral ureteral obstruction (UUO) was performed to obstruct the mid-ureter. A sham procedure, in which the left ureter was not obstructed, was applied to control mice. In situ perfusion with PBS and administration of 4% paraformaldehyde were performed before harvesting the kidneys, which were fixed in 4% paraformaldehyde and used for immunostaining. All experiments and methods involving live animals were performed after approval was received from the Institutional Animal Care and Use Committee of Wenzhou Medical University, China and in accordance with ethical guidelines for animal studies.