核转录因子KLF4在肾脏缺血再灌注损伤中的表达与保护机制探讨

The expression of Kruppel like factor 4 in renal ischemia/reperfusion injury and its possible protective mechanism

目的研究核转录因子KLF4在肾脏缺血再灌注损伤中的表达,并对其保护作用的可能机制进行探讨。方法 Realtime-RT-PCR方法检测大鼠双肾在缺血1 h,再灌注后不同时间点的KLF4表达情况,West-ern Blot方法检测KLF4在过氧化氢(H2O2)刺激的人胚肾细胞HEK293中的表达情况,采用基因转染技术过表达KLF4或抑制HEK293细胞中KLF4表达,观察KLF4的表达改变对H2O2损伤引起HEK293细胞死亡率的影响。结果 KLF4在大鼠肾脏缺血-再灌注时表达显著增高,在遭受H2O2损伤时,人胚肾细胞HEK293中KLF4的mRNA与蛋白表达也显著增高。过表达KLF4基因则能显著降低H2O2所致的HEK293细胞株的死亡率。抑制KLF4的表达能明显增加H2O2导致的HEK293肾细胞的死亡率。结论 KLF4极有可能是一个在肾脏缺血再灌注损伤过程中具有保护作用的核转录因子。

[Objective] To study the expression and effect of Kruppel like factor 4 （KLF4） in renal ischemia/reper- fusion （I/R） injury, and to identify its molecular mechanism. [ Methods ] To illustrate the response of KLF4 to renal I/R injury, reverse transcriptase-polymerase chain reaction （real time RT-PCR） was performed to determine the change of KLF4 expression of rat kidneys underwent I/R injury, western blot was used to determine the change in KLF4 expression of HEK293 cells underwent H202 stimulation. HEK293 cells over expressing KLF4 were estab- lished by stably transfecting pcDNA3.1-KLF4 plasmids, and the expression of KLF4 was inhibited by antisense oligodeoxynucleotides.Both cell lines were stimulated by H202, and the death rate of cells was determined. [ Results ] KLF4 mRNA in kidney tissues was up-regulated during renal ischemia/reperfusion injury in a time-dependent man- ner. The stimulation of H202 also up-regulated KLF4 mRNA and protein levels in a time-dependent manner in HEK293 cells.KLF4 over expression decreased the death rate of HEK293 cells stimulated by I-I202, while KLF4 defi- ciency increased the death rate. [ Conclusion ] KLF4 may be a protective transcription factor against renal ischemia/ reperfusion injury.