Dihydroartemisinin-induced unfolded protein response feedback attenuates ferroptosis via PERK/ATF4/HSPA5 pathway in glioma cells
Dihydroartemisinin-induced unfolded protein response feedback attenuates ferroptosis via PERK/ATF4/HSPA5 pathway in glioma cells
复制标题
双氢青蒿素诱导的未折叠蛋白反应反馈通过 PERK/ATF4/HSPA5 途径减轻神经胶质瘤细胞中的铁死亡
DOI：
10.1186/s13046-019-1413-7
复制
发表时间：
2019-09-13
影响因子：
11.3
通讯作者：
Zou, Zhengzhi
中科院分区：
文献类型：
--
作者：
Chen, Yibing;Mi, Yanjun;Zou, Zhengzhi
研究背景双氢青蒿素（DHA）通过铁依赖性活性氧（ROS）的产生发挥抗癌活性，这类似于铁凋亡（ferroptosis），一种新的细胞死亡形式。然而，DHA是否引起胶质瘤细胞的铁凋亡及其潜在的调控机制尚不清楚。方法在加入或不加入铁凋亡抑制剂的情况下，观察DHA对胶质瘤细胞增殖、细胞死亡、ROS和脂质ROS生成以及减少糖代谢的影响。使用分子方法评估胶质瘤细胞减弱DHA促铁作用的生物学机制。结果DHA可诱导胶质瘤细胞铁凋亡，表现为铁依赖性细胞死亡，同时伴有ROS产生和脂质过氧化。然而，DHA治疗同时通过增加热休克蛋白家族A（Hsp 70）成员5（HSPA 5）的表达激活了铁凋亡的反馈途径。机制上，DHA引起神经胶质瘤细胞中的内质网（ER）应激，这导致通过蛋白激酶R样ER激酶（PERK）上调激活转录因子4（ATF 4）诱导HSPA 5表达。随后的HSPA 5上调增加谷胱甘肽过氧化物酶4（GPX 4）的表达和活性，中和DHA诱导的脂质过氧化，从而保护胶质瘤细胞免于铁凋亡。使用siRNA或小分子抑制PERK-ATF 4-HSPA 5-GPX 4途径通过增加体外和体内的铁凋亡来增加胶质瘤细胞的DHA敏感性。结论铁凋亡可能是DHA抗胶质瘤的一种新机制，HSPA 5可能是DHA诱导的铁凋亡的负调节因子。因此，抑制负反馈通路将是增强DHA抗胶质瘤活性的一种有前景的治疗策略。
Background Dihydroartemisinin (DHA) has been shown to exert anticancer activity through iron-dependent reactive oxygen species (ROS) generation, which is similar to ferroptosis, a novel form of cell death. However, whether DHA causes ferroptosis in glioma cells and the potential regulatory mechanisms remain unclear. Methods Effects of DHA on the proliferation, cell death, ROS and lipid ROS generation as well as reduced gluthione consumption were assessed in glioma cells with or without ferroptosis inhibitor. The biological mechanisms by which glioma cells attenuate the pro-ferroptotic effects of DHA were assessed using molecular methods. Results DHA induced ferroptosis in glioma cells, as characterized by iron-dependent cell death accompanied with ROS generation and lipid peroxidation. However, DHA treatment simultaneously activated a feedback pathway of ferroptosis by increasing the expression of heat shock protein family A (Hsp70) member 5 (HSPA5). Mechanistically, DHA caused endoplasmic reticulum (ER) stress in glioma cells, which resulted in the induction of HSPA5 expression by protein kinase R-like ER kinase (PERK)-upregulated activating transcription factor 4 (ATF4). Subsequent HSPA5 upregulation increased the expression and activity of glutathione peroxidase 4 (GPX4), which neutralized DHA-induced lipid peroxidation and thus protected glioma cells from ferroptosis. Inhibition of the PERK-ATF4-HSPA5-GPX4 pathway using siRNA or small molecules increased DHA sensitivity of glioma cells by increasing ferroptosis both in vitro and in vivo. Conclusions Collectively, these data suggested that ferroptosis might be a novel anticancer mechanism of DHA in glioma and HSPA5 may serve as a negative regulator of DHA-induced ferroptosis. Therefore, inhibiting the negative feedback pathway would be a promising therapeutic strategy to strengthen the anti-glioma activity of DHA.