Unilateral ureteral obstruction (UUO) mouse model

A total of 24 male C57 BL/6J mice (age, 6–8 weeks; weight, 18–22 g) were housed in a temperature-controlled environment (18–22°C), with 50±5% humidity under a 12 h light/dark cycle and were provided with free access to food and water. The mice were randomly assigned to the Sham, UUO, UUO+miR-212 agomir and UUO+miR-212 antagomir groups (n=6 each). Mice in the UUO group were anesthetized by intraperitoneal injection of pentobarbital (50 mg/kg), and abdominal wall skin, muscle and peritoneal tissues were incised at the middle of the abdomen. Blunt forceps were used to separate the periureteral tissues and to expose the left ureter; the ureter was then ligated with 4-0 thread, and the peritoneum, muscle layer and skin were sutured layer by layer. The left ureters of the Sham group were separated without ligation, and the remaining methods were conducted in the same manner as those of the UUO group. Mice in the UUO+miR-212 agomir and UUO+miR-212 antagomir groups received an intravenous injection of 40 mg/kg miR-212 agomir or miR-212 antagomir, respectively, every 3 days after modeling; 14 days post-surgery, the mice were all sacrificed by dislocation of cervical vertebra, and the left kidneys were immediately removed.