Study about renal injury of unilateral ureteral obstruction model with time / 中国医师杂志

ABSTRACT

Objective:The unilateral (left) ureteral obstruction (UUO) model was established in mice to explore the changes of renal injury with time and the related mechanisms.Methods:Fifty mice were randomly divided into two groups sham group and UUO group (UUO model was made by unilateral ureteral ligation). The biochemical indexes, left kidney weight/final weight (LR/BW) and right kidney weight/final weight (RR/BW) of the two groups at different time points were observed, and the left kidney weight/right kidney weight ratio (LR/RR) was calculated. Hematoxylin-eosin (HE), Masson and periodic acid-Schiff (PAS) staining were used to detect the pathological changes of the kidney in mice. Immunofluorescence staining was used to observe the loss of peritubular capillaries (PTC), proliferation of renal parenchymal cells (Ki67 + cells), macrophages (CD68 + markers), infiltration of fibroblasts and expression of Wnt/β-catenin in the kidney of mice. Results:The weight of mice in UUO group decreased rapidly [(18.2±1.1)g vs (22.4±1.2)g] on the third day of modeling, then slowly increased until the 28th day, and significantly decreased [(17.5±0.8)g] on the 60th day; LR/RR and LR/BW increased significantly in the third day, and then decreased gradually; Renal function of mice in UUO group deteriorated significantly on the 60th day [serum creatinine (0.89±0.09)mg/dl, urea nitrogen (41.26±5.65)mg/dl]. In UUO group, renal tubulointerstitial fibrosis and glomerulosclerosis were observed under light microscope in the obstructed kidney; with the passage of time, PTC loss gradually increased; macrophages increased significantly in the left renal parenchyma at first, but began to decrease 28 days later; the number of fibroblasts increased significantly in the first 14 days of the obstructed side (left side) kidney, and then decreased to the normal level; There was no significant difference in the cell number of the non obstructive kidney between UUO group and sham group; The immunofluorescence intensity expression of Wnt/β- catenin of obstructive side (left side) in UUO group was significantly up-regulated in the first 14 days after renal injury, and decreased after 28 days.Conclusions:The development of UUO renal fibrosis involves many changes, including PTC loss, macrophage infiltration, fibroblast activation and expression, but these changes weaken with time.