铅暴露U251细胞差异表达基因分析

Analysis of Differentiation Expressed Genes of Human U251 Glioma Cells Exposed to Lead

为研究体外培养的人神经胶质瘤U251细胞(human U251glioma cells)铅暴露后基因表达的改变,分析脑中差异表达基因,探讨铅暴露与神经毒性之间的关系,使用浓度为400μg·mL-1乙酸铅暴露U251细胞8h和24h,设置空白对照,提取RNA.应用基因芯片方法寻找差异表达基因,芯片扫描结果经归一化处理,设定Ratio值<0.5或≥2.0为表达有差异基因.结果表明铅暴露U251细胞导致2840条基因差异表达,暴露8h和24h皆上调表达的基因有92条,皆下调表达的基因有85条,其中132条基因在脑中表达;通过与数据库资料比对,109条基因与其在脑表达情况一致,23条基因不一致(15条基因高表达,8条基因低表达).从实验结果可以看出铅暴露能够导致U251细胞基因表达改变,抑制细胞增殖和迁移,促进细胞凋亡,负调控T细胞免疫活性.导致与神经发生、细胞骨架形成相关基因表达下调,神经保护能力下降,铅暴露可能与神经变性疾病及退行性疾病发生有关.

To investigate the change of gene expression in human U251 glioma cells exposed to lead, and analyze the differential expression genes in brain, and relationship between lead exposure and neurotoxicity, The human U251 glioma cells were exposed to the 400μg·mL-1 lead for 8h and 24h. The total RNA was extracted, and microarray technique was used to screen out differentially expressed genes. The microarray data were normalized. The differentially expressed genes were accounted based on their ratio value were under0.5 or over≥2. Compared with the control group, exposure to lead led 2840 genes to show differential expression. There were 92 up-regulated genes and 85 down-regulated genes at 8h or 24h. Among of them, 132 genes expressed in brain, 15 genes showed over-expression, 8 genes showed under-expression. The results are concluded that lead exposure lead to gene differential expression in U251 cells, which may inhibit cell proliferation and migration, promote apoptosis, and affect regulation of T cell immunity. Furthermore, the down-regulated expression of related genes involve in neurodegenerative diseases and degenerative diseases.