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

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.