Shikonin shortens the circadian period: possible involvement of Top2 inhibition.
Shikonin shortens the circadian period: possible involvement of Top2 inhibition.
复制标题
紫草素缩短昼夜节律：可能与 Top2 抑制有关。
DOI：
10.1016/j.bbrc.2013.11.116
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Onishi Y.
中科院分区：
文献类型：
--
作者：
Ogawa Y;Kawano Y;Yamazaki Y;Onishi Y.
萘醌色素，紫草素，是从紫草中提取的天然产物，是中国传统草药治疗的有效成分。我们通过基于nih3t3衍生的稳定报告细胞的实时报告基因测定，确定了紫草素是缩短昼夜周期的候选者。与紫草素或烟叶皂苷孵育后，细胞的周期长度缩短，在不加这些化合物的情况下继续孵育后恢复到对照细胞的周期长度。这些结果表明，紫草素和依托草苷通过类似的机制可逆地缩短昼夜周期。拓扑异构酶II （Top2）特异性十烷磺酸测定证实，与依托泊苷一样，紫草素是Top2抑制剂。Shikonin被纳入细胞核，Top2位于bmal1启动子上，表明bmal1转录与Top2抑制之间存在关系。Top2asiRNA也缩短了周期长度，表明Top2asiRNA参与了这一过程。启动子实验表明，atop2asirna、依托泊苷和紫草素可降低ebmal1启动子活性。这些发现表明，Top2参与bmal1的转录并影响昼夜节律，而紫草素在哺乳动物细胞中对周期长度的控制有新的贡献。
The naphthoquinone pigment, shikonin, is a natural product derived fromLithospermumerythrorhizonand an active component of a Chinese traditional herbal therapeutic. We identified shikonin as a candidate for shortening the circadian period using real-time reporter gene assays based on NIH3T3-derived stable reporter cells. Period length that became shortened in cells incubated with shikonin or etoposide reverted to that of control cells after continued incubation without these compounds. These findings indicated that shikonin and etoposide shorten the circadian period reversibly and through similar mechanisms. Topoisomerase II (Top2)-specific decatenation assays confirmed that shikonin, liker etoposide, is a Top2 inhibitor. Shikonin was incorporated into the nucleus and Top2 was located in theBmal1promoter, suggesting the relationship betweenBmal1transcription and Top2 inhibition.Top2asiRNA also shortened period length, suggesting thatTop2is involved in this process. Promoter assays showed thatTop2asiRNA, etoposide and shikonin reduceBmal1promoter activity. These findings indicated that Top2 is involved inBmal1transcription and influences the circadian period, and that shikonin is a novel contributor to the control of period length in mammalian cells.