Regulation of the human corticotropin-releasing-hormone gene promoter activity by antidepressant drugs in Neuro2A and AtT-20 cells
Regulation of the human corticotropin-releasing-hormone gene promoter activity by antidepressant drugs in Neuro2A and AtT-20 cells
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DOI：
10.1038/sj.npp.1300379
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发表时间：
2004-04-01
影响因子：
7.6
通讯作者：
Lason, W
中科院分区：
文献类型：
--
作者：
Budziszewska, B;Jaworska-Feil, L;Lason, W
重度抑郁症通常与下丘脑-垂体-肾上腺（HPA）轴的亢进有关。临床有效的抗抑郁药物治疗可以通过减少促肾上腺皮质激素释放激素（CRH）的合成，使HPA轴的紊乱活动正常化，但这种作用的机制尚不清楚。为了了解抗抑郁药是否直接影响CRH基因启动子活性，我们研究了抗抑郁药对未分化和分化的神经2a细胞的影响，并比较了所选抗抑郁药对at -20细胞的影响。用与氯霉素乙酰转移酶（CAT）报告基因相关的人CRH启动子片段（-663 ~ +124 bp）稳定转染细胞。CRH基因启动子活性的调控在完整和分化的神经2a细胞和at -20细胞系中相似，cAMP/ pka依赖通路在CRH基因的刺激中起重要作用。发现在培养基中存在5天的丙咪嗪、阿米替林、地西帕明、氟西汀和米安色林以浓度依赖性的方式抑制未分化的神经2a细胞的基础hCRH基因启动子活性，而其他正在研究的药物（西酞普兰、天奈汀、莫氯贝胺、文拉法辛、雷波西汀、米氮平和米那西普兰）则无活性。在分化细胞中，除莫氯比胺（无影响）和天奈肽（增加）外，所有抗抑郁药均抑制hCRH基因转录。此外，在分化的细胞中，药物作用更强，在较低浓度下有效。在分化的细胞中，丙咪嗪和氟西汀可减弱福斯克林诱导的CAT活性，阿米替林和去西帕明也有较小程度的减弱，而其他药物则无活性。此外，丙咪嗪和氟西汀在CRH基因调控研究常用的at -20细胞系中也表现出中度抑制CRH基因启动子活性，而天奈汀则没有。这些结果表明，神经元样分化的神经- 2a细胞比垂体和完整的神经母细胞瘤更适合用于研究精神药物作用机制。抗抑郁药物抑制CRH基因启动子活性可能是其抑制HPA轴活性的一种分子机制。
Major depression is frequently associated with hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis. Clinically effective therapy with antidepressant drugs normalizes the disturbed activity of HPA axis, in part, by decreasing corticotropin-releasing hormone (CRH) synthesis, but the mechanism of this action is poorly recognized. In order to find out whether antidepressants directly affect CRH gene promoter activity, we studied their effect on undifferentiated and differentiated Neuro-2A cells, and for comparison the effect of the selected antidepressants on AtT-20 cells was also determined. The cells were stably transfected with a human CRH promoter fragment (-663 to +124 bp) linked to the chloramphenicol acetyltransferase (CAT) reporter gene. The regulation of CRH gene promoter activity is similar in Neuro-2A cells, both intact and differentiated, and in AtT-20 cell line, and cAMP/PKA-dependent pathway plays an important role in the stimulation of CRH gene. It was found that imipramine, amitryptyline, desipramine, fluoxetine, and mianserin, present in the culture medium for 5 days, in a concentration-dependent manner inhibited basal hCRH gene promoter activity in undifferentiated Neuro-2A cells, while other drugs under study (citalopram, tianeptine, moclobemide, venlafaxine, reboxetine, mirtazapine, and milnacipram) were inactive. In the differentiated cells, all examined antidepressants, except moclobemide (no effect) and tianeptine (increase), inhibited hCRH gene transcription. Moreover, in differentiated cells, the drugs acted stronger and were effective at lower concentrations. Forskolin-induced CAT activity was attenuated by imipramine and fluoxetine and to a lesser degree by amitriptyline and desipramine in differentiated cells, whereas other drugs were inactive. Moreover, imipramine and fluoxetine, but not tianeptine, showed moderate inhibitory effect on CRH gene promoter activity also in AtT-20 cell line, commonly used in CRH gene regulation studies. These results indicate that neuron-like differentiated Neuro-2A cells are a better model than pituitary and intact neuroblastoma to investigate the mechanism of psychotropic drug action. Inhibition of CRH gene promoter activity by antidepressant drugs may be a molecular mechanism by which these drugs inhibit the activity of HPA axis.