[Changes of miRNA-17-5p, miRNA-21 and miRNA-106a level during rat kidney ischemia-reperfusion injury].

Objective: Ischemia-reperfusion (I/R) is a main cause of acute kidney injury (AKI). The renal expression profiles of microRNA (miRNA) and time course of their changes after renal I/R were explored to screen acute AKI prognostic-related microRNAs and biomarkers.
Methods: The expression profile of miRNA was analyzed for detecting miRNAs in kidney after renal I/R injury. Real-time polymerase chain reaction (PCR) was performed to validate the results of microarray. And the relationship was examined between kidney injury and time course of changes in selected miRNAs.
Results: Twenty-one miRNAs were differentially expressed in kidney of rats with renal I/R injury. And 5 miRNAs had prominent differences. miR-17-5p, miR-21 and miR-106a were selected for further confirmation by quantitative real-time-PCR. And the results were consistent with those of microarry. During early stage (4 h) after I/R, the expression level of miR-17-5p significantly increased (P < 0.05). And it occurred earlier than those of BUN level and plasma concentration of neutrophil gelatinase-associated lipocalin (NGAL). Renal expressions of miR-21 and miR-106a were significantly elevated in ischemia 20 min and 30 min groups at 12 h and 24 h post-reperfusion (P < 0.01). And the trend was in accordance with those of BUN and NGAL.
Conclusions: miR-21, miR-17-5p and miR-106a are differentially expressed during different phases of renal I/R injury. And miR-17-5p is more sensitive than BUN and NGAL so that it is a more ideal biomarker for AKI.