Glutamine starvation inhibits snakehead vesiculovirus replication via inducing autophagy associated with the disturbance of endogenous glutathione pool
Glutamine starvation inhibits snakehead vesiculovirus replication via inducing autophagy associated with the disturbance of endogenous glutathione pool
复制标题
谷氨酰胺饥饿通过诱导与内源性谷胱甘肽库紊乱相关的自噬来抑制蛇头水泡病毒复制
DOI：
10.1016/j.fsi.2018.12.041
复制
发表时间：
2019-03-01
影响因子：
4.7
通讯作者：
Lin, Li
中科院分区：
文献类型：
--
作者：
Li, Cheng;Sun, Lindan;Lin, Li
自噬是一种细胞降解过程，在病毒感染中也起着重要作用。谷氨酰胺是合成谷胱甘肽的重要底物，谷胱甘肽是细胞内最丰富的含巯基化合物，在抗氧化防御和细胞内信号传导中起关键作用。存在由两种形式的谷胱甘肽组成的内源性细胞谷胱甘肽池，即还原形式（GSH）和氧化形式（GSSG）。GSH作为细胞内抗氧化剂，通过清除自由基和其他可导致自噬的活性氧（ROS）来维持细胞氧化还原稳态。在生理条件下，GSSG的浓度仅占总谷胱甘肽的1%左右，而应激条件可导致GSSG的瞬时增加。在我们以前的报告中，我们表明，在谷氨酰胺饥饿培养基中培养的SSN-1细胞中，黑鱼水泡病毒（SHVV）的复制被显著抑制，但其潜在的机制仍然是谜。在此，我们发现，添加L-丁硫氨酸-亚砜亚胺（BSO），一种GSH合成的特异性抑制剂，可以降低γ-谷氨酸-半胱氨酸连接酶（GCL）的活性和GSH水平，导致自噬和显着抑制SHVV在完全培养基中培养的SSN-1细胞中的复制。另一方面，在谷氨酰胺饥饿培养基中添加额外的GSH的SSN-1细胞中，SHVV的复制被拯救，自噬被抑制。此外，GSH合成的抑制并没有显着影响活性氧（ROS）的产生。但能显著降低GSH水平，提高GSSG水平，导致GSH/GSSG值降低，表明其促进了细胞的氧化应激。总之，本研究表明，谷氨酰胺饥饿通过诱导与内源性谷胱甘肽池的干扰相关的自噬来损害SHVV在SSN-1细胞中的复制。
Autophagy is a degradation cellular process which also plays an important role in virus infection. Glutamine is an essential substrate for the synthesis of glutathione which is the most abundant thiol-containing compound within the cells and plays a key role in the antioxidant defense and intracellular signaling. There is an endogenous cellular glutathione pool which consists of two forms of glutathione, i.e. the reduced form (GSH) and the oxidized form (GSSG). GSH serves as an intracellular antioxidant to maintain cellular redox homeostasis by scavenging free radicals and other reactive oxygen species (ROS) which can lead to autophagy. Under physiological conditions, the concentration of GSSG is only about 1% of total glutathione, while stress condition can result in a transient increase of GSSG. In our previous report, we showed that the replication of snakehead fish vesiculovirus (SHVV) was significant inhibited in SSN-1 cells cultured in the glutamine-starvation medium, however the underlying mechanism remains enigmatic. Here, we revealed that the addition of L-Buthionine-sulfoximine (BSO), a specific inhibitor of the GSH synthesis, could decrease the gamma-glutamate-cysteine ligase (GCL) activity and GSH levels, resulting in autophagy and significantly inhibition of the replication of SHVV in SSN-1 cells cultured in the complete medium. On the other hand, the replication of SHVV was rescued and the autophagy was inhibited in the SSN-1 cells cultured in the glutamine-starvation medium supplemented with additional GSH. Furthermore, the inhibition of the synthesis of GSH had not significantly affected the generation of reactive oxygen species (ROS). However, it significantly decreased level of GSH and enhanced the level of GSSG, resulting in the decrease of the value of GSH/GSSG, indicating that it promoted the cellular oxidative stress. Overall, the present study demonstrated that glutamine starvation impaired the replication of SHVV in SSN-1 cells via inducing autophagy associated with the disturbance of the endogenous glutathione pool.