Objective  To screen the differentially-expressed microRNAs (miRNAs) in mouse models with renal ischemia-reperfusion injury (IRI), aiming to offer foundation for unraveling the molecular mechanism of the incidence and progression of IRI.

  Methods  The mouse models with acute IRI were established by renal artery clamping. Fifteen mice were divided into the IRI group and sham surgery group (group E). The animals in the IRI group were subdivided into the A group (45 min ischemia followed by 24 h reperfusion), B group (25 min ischemia followed by 24 h reperfusion), C group (45 min ischemia followed by 4 h reperfusion) and D group (25 min ischemia followed by 4 h reperfusion) (n=3 for each group). The severity of IRI was evaluated by histological changes and renal function. The differentially-expressed miRNAs in the IRI mouse models at different ischemia time (25 and 45 min) and reperfusion time (4 and 24 h) were screened by using cluster analysis of miRNAs microarray data. The differential expression of miR-695 and miR-145 was validated by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR).

  Results  Both histological changes and renal function confirmed that the IRI mouse models were successfully established. Compared with the sham surgery group, 71 differentially-expressed miRNAs were detected in the IRI group including 30 down-regulated miRNAs and 40 up-regulated miRNAs. The results of qRT-PCR demonstrated that if the standardized expression level of miRNAs in the E group was 1, the relative expression levels of miR-695 and miR-145 were 11.82 and 0.31 in the IRI group (both P < 0.05), which were consistent with the chip results.

  Conclusions  After renal IRI, different changes occur in the gene expression profile of miRNAs. These differentially-expressed miRNAs act as molecular biomarkers for renal IRI with potential clinical and scientific research values.