The harmala alkaloid harmine is a modulator of circadian Bmal1 transcription
The harmala alkaloid harmine is a modulator of circadian Bmal1 transcription
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DOI：
10.1042/bsr20110002
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发表时间：
2012-02-01
影响因子：
4
通讯作者：
Yamazaki, Yoshimitsu
中科院分区：
文献类型：
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作者：
Onishi, Yoshiaki;Oishi, Katsutaka;Yamazaki, Yoshimitsu
生物节律是由细胞自主时钟系统协调的，该系统驱动时钟基因的节律级联。我们建立了一个测定系统，使用NIH 313细胞稳定表达Bmal1启动子驱动的荧光素酶报告基因，并使用它来分析昼夜节律振荡的基因。PKC（蛋白激酶C）的调节剂显示，激活剂和抑制剂分别代表短周期和长周期表型，这与报道的PKC对生物钟的影响一致，并验证了测定系统。我们研究了生物碱去氢骆驼蓬碱，Hoasca中，这具有广泛的药理作用，昼夜节律使用验证的测定系统的影响。去氢骆驼蓬碱剂量依赖性地延长了这一时间。此外，EMSA（电泳迁移率变动分析）和蛋白质印迹分析表明，去氢骆驼蓬碱增强ROR α（维甲酸相关孤儿受体α）的反式激活功能，可能是通过增加其核转位。ROR α的外源性表达也引起了长时间，证实了骆驼蓬碱所指示的表型。这些结果表明，去氢骆驼蓬碱通过增强ROR α功能来延长昼夜节律周期，并且去氢骆驼蓬碱是有助于控制哺乳动物细胞中周期长度的新候选物。
Biological rhythms are orchestrated by a cell-autonomous clock system that drives the rhythmic cascade of clock genes. We established an assay system using NIH 313 cells stably expressing the Bmal1 promoter-driven luciferase reporter gene and used it to analyse circadian oscillation of the gene. Modulators of PKC (protein kinase C) revealed that an activator and an inhibitor represented short- and long-period phenotypes respectively which were consistent with reported effects of PKC on the circadian clock and validated the assay system. We examined the effects of the alkaloid harmine, contained in Hoasca, which has a wide spectrum of pharmacological actions, on circadian rhythms using the validated assay system. Harmine dose dependently elongated the period. Furthermore, EMSA (electrophoretic mobility-shift assay) and Western-blot analysis showed that harmine enhanced the transactivating function of ROR alpha (retinoid-related orphan receptor alpha), probably by increasing its nuclear translocation. Exogenous expression of ROR alpha also caused a long period, confirming the phenotype indicated by harmine. These results suggest that harmine extends the circadian period by enhancing ROR alpha function and that harmine is a new candidate that contributes to the control of period length in mammalian cells.