转录因子CREB激活介导吗啡依赖SK-N-SH细胞的nNOS及fosB基因表达的调控机制

Activation of transcription factor CREB mediates the upregulation of nNOS and fosB genes in morphine-dependent SK-N-SH cells

目的 探讨吗啡依赖的SK- N -SH细胞表达神经元型一氧化氮合酶 (neuronalnitricoxidesynthase ,nNOS)及fosB基因的调控机制。方法 建立吗啡依赖及戒断细胞模型 ,体外合成含cAMP反应元件 (cAMPresponseelement ,CRE)序列的寡核苷酸 ,经硫代磷酸化修饰 ,作为单链寡核苷酸 (CRE transcriptionfactordecoyoligodeoxynucleotide ,CRE decoyODN)。分别采用电泳迁移率改变分析 (electrophoresismobilityshiftassay ,EMSA)及RT -PCR技术 ,检测CRE decoyODN对吗啡依赖及纳络酮急性戒断诱导的CREB的DNA结合活性、nNOS及fosBmRNA表达的影响。结果 吗啡依赖及纳络酮急性戒断使SK- N- SH细胞的CREB的DNA结合活性、nNOS及fosBmRNA明显升高 ,CRE decoyODN可特异抑制上述指标升高。结论 CREB的激活介导了吗啡依赖SK- N

Objective To investigate the mechanisms of morphine-dependent SK-N-SH cells in the regulation of the expressions of neuronal nitric oxide synthase (nNOS) and fosB genes. Methods Morphine-dependent and naloxone-precipitated cellular model systems were established. A synthetic single-stranded phosphorothioate oligodeoxynucleotide composed of the cAMP response element (CRE) sequence was used as CRE-transcription factor decoy oligodeoxynucleotide (CRE-decoy ODN) and was added to the culture medium. The effects of CRE-decoy ODN on the DNA-binding activity of CREB and the expressions of nNOS and fosB genes in morphine-dependent and naloxone-precipitated SK-N-SH cells were detected by electrophoresis mobility shift assay (EMSA) and RT-PCR, respectively. Results Morphine dependence and naloxone-precipitated withdrawal significantly activated the DNA-binding activity of CREB and the expressions of nNOS and fosB genes. CRE-decoy ODN could penetrate into cells and specifically and stably downregulate these indexes. Conclusion The activation of transcription factor CREB can mediate the upregulation of the expressions of nNOS and fosB genes in morphine-dependent SK-N-SH cells.