miRNA表达谱在大鼠肾缺血再灌损伤过程中的变化

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

目的 观察大鼠肾缺血再灌注损伤中miRNA表达谱变化及筛选出的miRNAs在肾缺血再灌注损伤肾组织中时间变化以寻找急性肾损伤早期诊断和预后评价的目标miRNAs.方法 利用miRNA微流体芯片技术检测大鼠正常肾脏及缺血再灌注损伤肾脏miRNA表达谱的差异,并使用实时定量聚合酶链反应（qRT-PCR）进行验证.筛选出差异最为显著miRNAs,并分析其在再灌注后水平的时间变化及和肾损伤的关系.结果 有明显差异表达的miRNA共有21个,其中有5个miRNAs差异最为显著;miR-17-5p、miR-21和miR-106a肾组织表达水平和芯片结果保持一致.缺血再灌注早期（再灌注4h后）肾组织miR-17-5p水平即出现明显升高（P＜0.05）,早于BUN和NGAL明显变化时间;缺血30 min组和缺血20 min组分别于再灌注12 h和24h后其miRNA-21、miR-106a水平开始显著升高（P＜0.01）,和血BUN和NGAL水平变化趋势一致.结论 miR-17-5 p、miR-21、miR-106a在肾缺血再灌注损伤的不同阶段及不同缺血时间会发生不同程度的表达量变化,且miR-17-5p早于血NGAL及BUN开始出现升高,可能是一种较之BUN和NGAL更为优越的评估AKI的有效标志物.

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 realtime-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.