当前位置: X-MOL 学术Neurochem. Int. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Hydrogen peroxide triggers an increase in cell surface expression of system xc- in cultured human glioma cells.
Neurochemistry international ( IF 4.2 ) Pub Date : 2019-12-23 , DOI: 10.1016/j.neuint.2019.104648
Leah A Chase 1 , Mary VerHeulen Kleyn 2 , NaTasha Schiller 1 , Abby Goltz King 2 , Guillermo Flores 1 , Sasha Balcazar Engelsman 2 , Christina Bowles 3 , Sara Lang Smith 3 , Anne E Robinson 1 , Jeffrey Rothstein 4
Affiliation  

System xc- exchanges extracellular cystine for intracellular glutamate across the plasma membrane of many cell types. One of the physiological roles of System xc- is to provide cystine for synthesis of the antioxidant glutathione. Here we report that hydrogen peroxide (H2O2) triggers the translocation of System xc- to the plasma membrane within 10 min of the initial exposure. Specifically, we observed a three-fold increase in 35S-l-cystine uptake following a 10 min exposure to 0.3 mM H2O2. This effect was dose-dependent with an EC50 for H2O2 of 65 μM. We then used cell surface biotinylation analysis to test the hypothesis that the increase in activity is due to an increased number of transporters on the plasma membrane. We demonstrated that the amount of transporter protein, xCT, localized to the plasma membrane doubles within 10 min of H2O2 exposure as a result of an increase in its delivery rate and a reduction in its internalization rate. In addition, we demonstrated that H2O2 triggered a rapid decrease in total cellular glutathione which recovered within 2 h of the oxidative insult. The kinetics of glutathione recovery matched the time course for the recovery of xCT cell surface expression and System xc- activity following removal of the oxidative insult. Collectively, these results suggest that oxidants acutely modulate the activity of System xc- by increasing its cell surface expression, and that this process may serve as an important mechanism to increase de novo glutathione synthesis during periods of oxidative stress.

中文翻译:

过氧化氢触发了培养的人类神经胶质瘤细胞中系统xc-的细胞表面表达的增加。

System xc-通过多种细胞类型的质膜将细胞外胱氨酸交换为细胞内谷氨酸。System xc-的生理作用之一是为合成抗氧化剂谷胱甘肽提供胱氨酸。在这里,我们报道过氧化氢(H2O2)在初始暴露后10分钟内触发系统xc-向质膜的移位。具体而言,我们观察到暴露于0.3 mM H2O2 10分钟后35S-1-胱氨酸的摄取增加了三倍。该效应是剂量依赖性的,H2O2的EC50为65μM。然后,我们使用细胞表面生物素化分析来检验以下假设:活性增加是由于质膜上转运蛋白数量增加所致。我们证明了转运蛋白xCT的量 H2O2暴露速率增加和内化速率降低的结果是,定位于质膜的分子在H2O2暴露后10分钟内会翻倍。此外,我们证明了H2O2触发了总细胞内谷胱甘肽的快速下降,谷胱甘肽在氧化损伤后2小时内恢复。去除氧化损伤后,谷胱甘肽恢复的动力学符合xCT细胞表面表达恢复和系统xc-活性恢复的时间过程。总体而言,这些结果表明,氧化剂通过增加细胞表面表达来急剧调节System xc-的活性,并且该过程可能是增加氧化应激期间谷胱甘肽从头合成的重要机制。此外,我们证明了H2O2触发了总细胞内谷胱甘肽的快速下降,而谷胱甘肽在氧化损伤后2小时内就恢复了。去除氧化损伤后,谷胱甘肽恢复的动力学符合xCT细胞表面表达恢复和系统xc-活性恢复的时间过程。总体而言,这些结果表明,氧化剂通过增加细胞表面表达来急剧调节System xc-的活性,并且该过程可能是增加氧化应激期间谷胱甘肽从头合成的重要机制。此外,我们证明了H2O2触发了总细胞内谷胱甘肽的快速下降,而谷胱甘肽在氧化损伤后2小时内就恢复了。去除氧化损伤后,谷胱甘肽恢复的动力学符合xCT细胞表面表达恢复和系统xc-活性恢复的时间过程。总体而言,这些结果表明,氧化剂通过增加细胞表面表达来急剧调节System xc-的活性,并且该过程可能是增加氧化应激期间谷胱甘肽从头合成的重要机制。去除氧化损伤后,谷胱甘肽恢复的动力学符合xCT细胞表面表达恢复和系统xc-活性恢复的时间过程。总体而言,这些结果表明,氧化剂通过增加细胞表面表达来急剧调节System xc-的活性,并且该过程可能是增加氧化应激期间谷胱甘肽从头合成的重要机制。去除氧化损伤后,谷胱甘肽恢复的动力学符合xCT细胞表面表达恢复和系统xc-活性恢复的时间过程。总体而言,这些结果表明,氧化剂通过增加细胞表面表达来急剧调节System xc-的活性,并且该过程可能是增加氧化应激期间谷胱甘肽从头合成的重要机制。
更新日期:2019-12-23
down
wechat
bug