Oridonin stabilizes retinoic acid receptor alpha through ROS-activated NF-κB signaling.
Oridonin stabilizes retinoic acid receptor alpha through ROS-activated NF-κB signaling.
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冬凌草甲素通过 ROS 激活的 NF-κB 信号稳定视黄酸受体 α
DOI：
10.1186/s12885-015-1219-8
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发表时间：
2015-04-10
期刊：
影响因子：
3.8
通讯作者：
Yan H
中科院分区：
文献类型：
--
作者：
Cao Y;Wei W;Zhang N;Yu Q;Xu WB;Yu WJ;Chen GQ;Wu YL;Yan H
视黄酸受体α（RARα）在造血细胞分化等生物学过程中发挥重要作用，而RARα功能异常则参与了某些疾病的发病机制，包括癌症，尤其是急性早幼粒细胞白血病（APL）。近年来，从冬凌草中分离得到的二萜类化合物冬凌草甲素（oridonin）被证实可以通过增加RAR α的蛋白水平来调节RARα的表达。然而，这种作用的潜在分子机制尚未完全阐明。在APL细胞株NB 4中，采用Western blot和实时荧光定量RT-PCR分析冬凌草甲素对RARα蛋白的影响。流式细胞术检测细胞内活性氧（ROS）水平。核因子-κ B（NF-κB）信号传导和冬凌草甲素的作用之间的关联使用特异性抑制剂、shRNA基因敲低和免疫荧光测定来评估。此外，原代白血病细胞与冬凌草甲素处理，并在本研究中进行了分析。RARα在其配体全反式维甲酸（ATRA）存在下具有转录活性。冬凌草甲素能显著稳定RARα蛋白，使其保持转录活性。冬凌草甲素也适度增加细胞内ROS水平，而用ROS清除剂N-乙酰基-L-半胱氨酸（NAC）预处理，显着消除了冬凌草甲素对RARα的稳定作用。更有趣的是，直接暴露于低浓度H2 O2也增加RARα蛋白而不是mRNA水平，表明ROS在冬凌草甲素稳定RARα蛋白中的作用。进一步研究表明，NAC可拮抗冬凌草甲素诱导的NF-κB信号通路的激活，而NF-κB信号通路抑制剂Bay 11-7082可有效阻断冬凌草甲素诱导的RARα蛋白水平的升高。与此一致，I κ B α（A32/36）（Iκ B α的超阻遏物形式）的过表达或NF-κB-p65敲低抑制了冬凌草甲素或H2 O2诱导的RARα稳定性。最后，肿瘤坏死因子α（TNFα），一种经典的NF-κB信号传导激活剂，调节RARα蛋白的稳定性。冬凌草甲素通过增加细胞ROS水平稳定RARα蛋白，从而激活NF-κB信号通路。
Retinoic acid receptor alpha (RARα) plays an essential role in the regulation of many biological processes, such as hematopoietic cell differentiation, while abnormal RARα function contributes to the pathogenesis of certain diseases including cancers, especially acute promyelocytic leukemia (APL). Recently, oridonin, a natural diterpenoid isolated from Rabdosia rubescens, was demonstrated to regulate RARα by increasing its protein level. However, the underlying molecular mechanism for this action has not been fully elucidated. In the APL cell line, NB4, the effect of oridonin on RARα protein was analyzed by western blot and real-time quantitative RT-PCR analyses. Flow cytometry was performed to detect intracellular levels of reactive oxygen species (ROS). The association between nuclear factor-kappa B (NF-κB) signaling and the effect of oridonin was assessed using specific inhibitors, shRNA gene knockdown, and immunofluorescence assays. In addition, primary leukemia cells were treated with oridonin and analyzed by western blot in this study. RARα possesses transcriptional activity in the presence of its ligand, all-trans retinoic acid (ATRA). Oridonin remarkably stabilized the RARα protein, which retained transcriptional activity. Oridonin also moderately increased intracellular ROS levels, while pretreatment with the ROS scavenger, N-acetyl-l-cysteine (NAC), dramatically abrogated RARα stabilization by oridonin. More intriguingly, direct exposure to low concentrations of H2O2 also increased RARα protein but not mRNA levels, suggesting a role for ROS in oridonin stabilization of RARα protein. Further investigations showed that NAC antagonized oridonin-induced activation of NF-κB signaling, while the NF-κB signaling inhibitor, Bay 11–7082, effectively blocked the oridonin increase in RARα protein levels. In line with this, over-expression of IκΒα (A32/36), a super-repressor form of IκΒα, or NF-κB-p65 knockdown inhibited oridonin or H2O2-induced RARα stability. Finally, tumor necrosis factor alpha (TNFα), a classical activator of NF-κB signaling, modulated the stability of RARα protein. Oridonin stabilizes RARα protein by increasing cellular ROS levels, which causes activation of the NF-κB signaling pathway.
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DOI：
10.1084/jem.20100523
发表时间：
2010-04-12
期刊：
The Journal of experimental medicine
影响因子：
--
作者：
Abdel-Wahab O;Levine RL
通讯作者：
Levine RL
冬凌草甲素与三氧化二砷对肝癌细胞的协同抗肿瘤活性
影响因子：
5.2
作者：
Chen, Guo;Wang, Ke;Hua, Zi-Chun
通讯作者：
Hua, Zi-Chun
影响因子：
11.4
作者：
Duprez, E;Wagner, K;Tenen, DG
通讯作者：
Tenen, DG
影响因子：
5.7
作者：
Ikezoe, T;Yang, Y;Taguchi, H
通讯作者：
Taguchi, H
影响因子：
3.6
作者：
Leung, CH;Grill, SP;Cheng, YC
通讯作者：
Cheng, YC