HIF-1α与SDF-1α/CXCR4在星形胶质细胞缺氧应激过程中的调控机制与作用

Analyses of regulation mechanisms and roles of the HIF-1α and SDF-1α/CXCR4 on astrocytes during hypoxia stress

目的探讨星形胶质细胞缺氧模型中缺氧诱导因子-1α(hypoxia-inducible factor-1α,HIF-1α)与基质衍生因子-1α/趋化因子受体(stromal cell derived factor 1α/chemokine receptor 4、SDF-1α/CXCR4)通路在缺氧应激过程中的调控机制与作用。方法原代培养SD大鼠星形胶质细胞并构建缺氧模型,采用不同浓度梯度与时间CoCl2处理后,使用RT-PCR检测缺氧前后HIF-1α和SDF-1α的mRNA表达情况,并采用ELISA的方法检测SDF-1α的分泌情况。针对HIF-1α基因序列设计siRNA,诱导星形胶质细胞缺氧模型内HIF-1α基因沉默并检测HIF-1α、SDF-1α的mRNA表达情况与SDF-1α的分泌水平的变化情况。结果研究显示星形胶质细胞在CoCl2模拟的缺氧环境下HIF-1α和SDF-1αmRNA表达的水平均上调。另一方面,沉默HIF-1α基因的星形胶质细胞在缺氧环境中SDF-1α的表达水平无显著性升高。结论缺氧刺激上调星形胶质细胞SDF-1α的表达是通过上调HIF-1α表达介导的。HIF-1α与SDF-1α/CXCR4之间可能存在调控关系。

Objective To investigate the pathway and the role of the regulatory mechanism of hypoxiainducible factor-1α（HIF-1α） and stromal cell derived factor 1α/chemokine receptor 4（SDF-1α/CXCR4） in astrocytes model during hypoxia stress.Methods Hypoxia SD rat astrocytes model was constructed and treated with different concentrations of cobalt chloride for different hours.mRNA expression of HIF-1α and SDF-1α was tested by RT-PCR and ELISA method was used to detect the secretion of SDF-1α.HIF-1α was gene silenced by siRNA in the astrocytes.The mRNA expression of HIF-1α and SDF-1α expression and secretion were detected.Results The hypoxia stress model was successfully constructed.The mRNA expression of HIF-1α and SDF-1α were increased.On the other hand,the secretion of SDF-1α were not significantly increased in the astrocytes model silenced HIF-1α gene in the hypoxic environment.Conclusion This study indentified HIF-1α and SDF-1α/CXCR4 play an important regulatory role in astrocytes during hypoxia stress.It is via up-regulation expression of HIF-1α that the up-regulation expression of SDF-1α induced by hypoxia in the astrocytes.