DIRECT INTERACTIONS OF METHAMPHETAMINE WITH THE NUCLEUS.

通过电泳迁移位移法评估甲基苯丙胺（methamphetamine， METH）对细胞核中转录因子AP-1和cAMP反应元件结合蛋白（response element-binding protein， CREB）可能的直接影响。体外将甲基安非他明添加到脑组织核提取物中，增加了这两种转录因子的dna结合活性。此外，给小鼠注射甲基安非他明诱导AP-1和CREB结合的增加，通过将核提取物与抗甲基安非他明抗体预孵化来减少AP-1和CREB的结合。我们还利用抗甲基苯丙胺抗体的免疫荧光实验检测了甲基苯丙胺在中脑神经元细胞中的细胞分布。甲基苯丙胺样免疫反应性在甲基苯丙胺处理后4-6小时在细胞质中积累。此外，meth处理细胞的细胞核中也观察到meth阳性信号。本研究首次证明甲基苯丙胺不仅在细胞质中重新分布，而且在细胞核中重新分布，从而对dna结合蛋白复合物产生直接影响。

Possible direct effects of methamphetamine (METH) on transcription factors AP-1 and cAMP response element-binding protein (CREB) in the nucleus were assessed by electrophoretic mobility-shift assay. In vitro addition of METH to nuclear extract from brain tissue increased DNA-binding activities of both transcription factors. In addition, injections of METH to mice induced increases in the binding of AP-1 and CREB, which were depleted by preincubating the nuclear extract with anti-METH antibody. We also examined the cellular distribution of METH in mesencephalic neuronal cells using an immunofluorescence experiment with anti-METH antibody. METH-like immunoreactivity was seen to accumulate in the cytosol 4-6 h after the METH treatment. Furthermore, METH-positive signals were also observed in the nuclei of the METH-treated cells. The present study is the first demonstration that METH can have direct effects on DNA-binding protein complex by redistributing not only in the cytosol but also into the nucleus.