Department of Neurosurgery, First Hospital of Jilin University, Changchun, 130021, China; Research Center of Neuroscience, First Hospital of Jilin University, Changchun, 130021, China.
Department of Anesthesiology, First Hospital of Jilin University, Changchun, 130021, China.
Cancer Lett. 2018 Jul 1;425:31-42. doi: 10.1016/j.canlet.2018.03.046. Epub 2018 Mar 30.
RIP1 and RIP3 are necroptosis initiators, but their roles in regulation of glycolysis remain elusive. In this study, we found shikonin activated RIP1 and RIP3 in glioma cells in vitro and in vivo, which was accompanied with glycolysis suppression. Further investigation revealed that shikonin-induced decreases of glucose-6-phosphate and pyruvate and downregulation of HK II and PKM2 were significantly prevented when RIP1 or RIP3 was pharmacologically inhibited or genetically knocked down with SiRNA. Moreover, shikonin also triggered accumulation of intracellular HO and depletion of GSH and cysteine. Mitigation of intracellular HO via supplement of GSH reversed shikonin-induced glycolysis suppression. The role of intracellular HO in regulation of glycolysis suppression was further confirmed in the cells treated with exogenous HO. Notably, inhibition of RIP1 or RIP3 prevented intracellular HO accumulation, which was correlated with preventing shikonin-induced downregulation of x-CT and depletion of GSH and cysteine. In addition, supplement of pyruvate effectively inhibited shikonin- or exogenous HO-induced accumulation of intracellular HO and glioma cell death. Taken together, we demonstrated in this study that RIP1 and RIP3 contributed to shikonin-induced glycolysis suppression via increasing intracellular HO.
RIP1 和 RIP3 是细胞坏死的启动子，但它们在糖酵解调控中的作用仍不清楚。在本研究中，我们发现紫草素在体外和体内激活了胶质瘤细胞中的 RIP1 和 RIP3，同时伴随着糖酵解的抑制。进一步的研究表明，当用药理学抑制剂或 siRNA 基因敲低 RIP1 或 RIP3 时，紫草素诱导的葡萄糖-6-磷酸和丙酮酸减少以及 HK II 和 PKM2 下调明显受到阻止。此外，紫草素还触发了细胞内 HO 的积累和 GSH 和半胱氨酸的耗竭。通过补充 GSH 来减轻细胞内 HO 可逆转紫草素诱导的糖酵解抑制。在用外源性 HO 处理的细胞中进一步证实了细胞内 HO 在调节糖酵解抑制中的作用。值得注意的是，抑制 RIP1 或 RIP3 可防止细胞内 HO 的积累，这与阻止紫草素诱导的 x-CT 下调以及 GSH 和半胱氨酸耗竭有关。此外，补充丙酮酸可有效抑制紫草素或外源性 HO 诱导的细胞内 HO 积累和胶质瘤细胞死亡。综上所述，本研究表明，RIP1 和 RIP3 通过增加细胞内 HO 促进了紫草素诱导的糖酵解抑制。
