Reduction in miRNA-125b-5p levels is associated with obstructive renal injury.

Obstructive renal injury is a common disease that leads to progressive glomerulosclerosis, tubulointerstitial fibrosis and loss of renal function. MicroRNAs (miRNAs/miRs) are small non-coding molecules that may be involved in the progression of many renal diseases. The aim of the present study was to investigate the roles of miRNAs, including miR-125b, miR-326 and miR-324p, in obstructive renal injury. Blood samples were collected from 91 patients with ureteral obstruction and 76 controls to examine renal function. In addition, the levels of miR-125b, miR-326 and miR-324p in patients with ureteral obstruction and controls were determined by the reverse transcription-quantitative polymerase chain reaction. Furthermore, the relationship between miRNA levels and renal function was evaluated by the Mann-Whitney U test. Upregulated levels of serum creatinine (SCr) in patients with ureteral obstruction were observed, identifying the injury of renal function. Although the expression levels of miR-324-5p [1.003 (0.391-2.279) vs. 0.934 (0.579-1.539), P=0.300] and miR-326 [0.840 (0.180-2.020) vs. 0.949 (0.507-1.702), P=0.050] presented no significant difference, the levels of miR-125b-5p [0.755 (0.210-2.110) vs. 0.960 (0.390-1.770), P=0.002] in patients with ureteral obstruction were significantly lower than those in controls. These results indicated that there is a stronger correlation of miR-125b-5p with the occurrence of ureteral obstruction, especially for the female (P=0.0171) and elderly (P=0.0142). Furthermore, the levels of miR-125b-5p (r=-0.175, P=0.038) were closely associated with the serum levels of SCr, suggesting a key role of miR-125b-5p in renal dysfunction. Thus, these findings suggested that miR-125b-5p in patients with ureteral obstruction correlated with renal function, and may be a potential biomarker for obstructive renal injury.