Establishment of a mouse model of chronic renal insufficiency induced by repeated administration of cisplatin / 中国实验动物学报

ABSTRACT

Objective To observe the changes of renal tubular injury and the extent of interstitial fibrosis in the C57BL/6 mouse models of chronic kidney disease(CKD),and provide experimental animal evidence for study of the pro-gression of acute kidney injury(AKI)to chronic kidney disease as well as its mechanisms. Methods Twenty-four 8-week-old male C57BL/6 mice were randomly and equally divided into control group, low-dose, medium-dose, and high-dose cisplatin groups,6 mice in each group. Mice in the cisplatin groups were administrated with 5,7 or 10 mg/kg cispla-tin by intraperitoneal injection once a week for 4 weeks. Plasma creatinine and 24-hour urinary protein were detected to as-sess the renal function. The mice were sacrificed, and plasma and kidney samples were collected for subsequent tests. Pathological changes were observed using periodic acid-Schiff(PAS)staining. To evaluate renal tubules injury, the ex-pression of kidney injury molecule 1(KIM-1)was examined by immunohistochemistry and the level of urinary N-Acetyl-β-D-glucosaminidase was detected with a commercial kit. The infiltration of CD3-positive T cells and F4/80-positive macro-phages was observed by immunohistochemistry(IHC)and immunofluorescence. The expression of collagen I and α-smooth muscle actin(α-SMA)were tested by immunohistochemistry to assess the renal fibrosis, while total kidney collagen was detected by Picrosirius red staining. Results In contrast to the normal control group,the kidney injury became more seri-ous in the cisplatin-treated mice as cisplatin concentration increased. Particularly,significant kidney damage was observed in the high-dose cisplatin group. Compared with the control group,the plasma creatinine and 24-hour urinary protein were significantly increased in the high-dose cisplatin group(P<0.05 and P<0.001)indicating impaired renal function. Mor-phologically,numerous clear vacuoles and necrosis were present in renal tubule epithelial cells in the high-dose cisplatin group. The expression of KIM-1 was markedly up-regulated and the level of urinary NAG was elevated. Infiltration of CD3-positive T cells and F4/80-positive macrophages was enhanced in the mice of high-dose cisplatin group. Data from immuno-histochemistry and picrosirius red staining showed that mice of the high-dose cisplatin group developed renal fibrosis evi-denced by markedly up-regulated expression of collagen I and α-SMA. Conclusions Repeated administration of 10 mg /kg cisplatin for 4 weeks can induce chronic renal insufficiency in mice,which may serve as a novel model for the research on underlying mechanisms of progression from acute kidney injury to chronic kidney disease.