【摘要】 本文利用 c-fos ASO(反义链全部硫代磷酸化修饰 )技术阻断 c-fos的表达 ,观察此项处理对亚硒酸钠在体外培养皮质神经细胞致凋亡作用和相关基因表达改变的影响。结果显示 :( 1) c-fos ASO可阻断亚硒酸钠的致凋亡作用 ,且有一定的剂量和时间依赖性 ;用琼脂糖凝胶电泳分析由各个时间点提取的 DNA片段 ,与对照组比较 ,c-fos ASO能明显阻断亚硒酸钠诱导的典型的 DNA梯型 ;用流式细胞仪检测得到的 DNA含量直方图也显示 ,在 c-fos ASO处理后 ,与对照组比较 ,亚硒酸钠引起的亚二倍体峰变小 ;( 2 )用 RT-PCR法检测表明 ,在用 c-fos ASO和亚硒酸钠处理皮质神经细胞后 ,不仅阻断了 c-fos表达的上调 ,对其它几种基因表达的改变也有不同的影响 ,与对照组比较 ,c-fosm RNA在各个时间点 ( 0 .5、1、2、4和 2 4h)不再上升 ,bcl-2 m RNA则不再下降 ,bax m RNA和 ACh E m RNA都不再上升 ;唯一不同的是 ,p5 3m RNA的变化趋势则与未经 c-fos ASO预处理时基本相同 ,在多数时间点两组 p-5 3m RNA水平之间无显著性差异 ( P>0 .0 5 ) ,说明此基因的表达基本不受 c-fos ASO作用的影响。上述结果提示 ,亚硒酸钠诱导的神经元凋亡可能是一组级联式基因表达更变的结果 ,c-fos是其中的一个组成成员 ,它的表达改变被阻断后 ,处于它下游?更多还原

【Abstract】 To investigate the role of immediate-early gene c-fos in sodium selenite-induced apoptosis and its position in a possible cascade of apoptogenic genes, we compared the time-courses of expression for 5 related genes, including c-fos, during the apoptosis induced by sodium selenite with or without blockage of c-fos expression by adding c-fos antisense oligodeoxynucleotide (ASO) in cultured cortical neurons. The results showed that: (1) in control experiments without c-fos ASO adding, 0.5 μmol/L sodium selenite-induced apoptosis as revealed by electrophoretic and flow cytometric examinations; at the same time, sodium selenite also induced down-regulation of bcl-2 mRNA expression and up-regulations of mRNAs related to bax, c-fos, p53, and acetylcholinesterase (AChE) genes; (2) in similar experimental conditions with c-fos ASO cotreatment, the sodium selenite-induced apoptosis was blocked with the up-regulation of p53 expression still emerging as before, while the changes in expressions of bcl-2, bax, AChE genes were reversed at the same time. The results suggest that c-fos ASO could play a protective role upon cortical neurons from suffering apoptosis induced by sodium selenite, and there might exist a cascade of gene expressions with p53 and c-fos genes being regulated upstream and then bcl-2, bax, and AChE genes being regulated downstream.更多还原