低氧诱导因子1α对钾-氯协同转运子1启动子调控作用的研究

The regulation function of HIF-1α to the promoter of K-Cl cotransporter

目的:钾-氯共同转运子1(KCC1)启动子中有一推断的低氧诱导因子1α(HIF-1α)的结合位点,通过表达HIF-1α,探索该位点是否为真正的低氧诱导因子结合位点。方法:分别用KCC1野生型启动子和HIF-1α位点变异的KCC1启动子,与HIF-1α质粒或对照载体共转染HEK293细胞,用荧光素酶功能分析的方法观测HIF-1α对KCC1启动子活性的影响,用RT-PCR方法比较转染与不转染HIF-1α对KCC1表达水平的差异。结果:转染HIF-1α后野生型KCC1启动子荧光素酶活性为对照Z组的2.39倍,而变异的HIF-1α位点的KCC1启动子荧光素酶活性则在转染与不转染HIF-1α条件下差异无统计学意义,在HIF-1α转染条件下KCC1表达水平高于对照组的水平,HIF-1α转染条件下是HIF-1α不转染条件下表达量的3.19倍。结论:首次证实了HIF-1α可直接增强KCC1启动子的活性,HIF-1α可调节KCC1的表达水平。

Objective To explore whether an inference binding site of hypoxia inducible factor-1α （HIF- 1α） in KCC1 promoter area is the really HIF binding site through testing HIF-1α expression. Methods Plasmid of wild type KCC1 promoter and KCC1 promoter with mutation point at HIF-1α site were cotransfected in HEK293 cell, with HIF-1α or with control vector, respectively. The effects of HIF-1α on KCC1 promoter activities were observed by assaying luciferase activities. The different KCC1 expressions on contransfected and untransfected HIF-1α were analyzed by RT-PCR. Results The luciferase activities of wild type KCC1 promoter cotransfected with HIF-1α was 2.39 times higher than that of promoter cotransfected with control vector, while the luciferase activities of KCC1 promoter point mutated at HIF-1α binding site was no statistical different between contransfected and untransfected with HIF-1α. KCC1 expression in HIF-1α transfection condition was 3.19 times higher than that in control. Conclusion It is first proved that HIF-1α can directly increase the activity of KCC1 promoter and HIF-1α can regulate KCC1 expression.