The Glutathione Reductase GSR-1 Determines Stress Tolerance and Longevity in Caenorhabditis elegans
The Glutathione Reductase GSR-1 Determines Stress Tolerance and Longevity in Caenorhabditis elegans
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DOI：
10.1371/journal.pone.0060731
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发表时间：
2013-04-08
期刊：
影响因子：
3.7
通讯作者：
Liebau, Eva
中科院分区：
文献类型：
--
作者：
Lueersen, Kai;Stegehake, Dirk;Liebau, Eva
谷胱甘肽（GSH）和GSH依赖酶在细胞解毒过程中发挥关键作用，使生物体能够科普各种内部和环境压力。然而，它往往是不清楚的，复杂的谷胱甘肽代谢的组成部分是需要对某种应激耐受。为了解决这个问题，在秀丽隐杆线虫中进行了小规模的RNAi筛选，其中GSH相关基因被系统地敲低，随后分析了蠕虫在亚致死浓度的亚砷酸盐和氧化还原循环剂胡桃醌下的存活率。虽然γ-谷氨酰半胱氨酸合成酶的敲低导致在亚砷酸盐胁迫条件下存活率降低，但GSR-1（谷胱甘肽还原酶）被证明是胡桃醌胁迫条件下存活所必需的。gsr-1是在C.优美的在正常实验室条件下，GSR-1的敲除几乎不影响总谷胱甘肽水平，也不影响还原型谷胱甘肽/谷胱甘肽二硫化物（GSH/GSSG）比率。然而，当GSSG再循环受损gsr-1（RNAi），诱导GSH的合成，但反之亦然。此外，GSSG再循环的影响在氧化应激条件下被加强，解释了gsr-1（RNAi）敲低对胡桃醌耐受性的巨大影响。因此，GSR-1的过表达能够增加胁迫耐受性。此外，SKN-1调节的GSR-1表达水平也影响C的寿命。elegans，强调GSH氧化还原状态在这两个过程中发挥的关键作用。
Glutathione (GSH) and GSH-dependent enzymes play a key role in cellular detoxification processes that enable organism to cope with various internal and environmental stressors. However, it is often not clear, which components of the complex GSH-metabolism are required for tolerance towards a certain stressor. To address this question, a small scale RNAi-screen was carried out in Caenorhabditis elegans where GSH-related genes were systematically knocked down and worms were subsequently analysed for their survival rate under sub-lethal concentrations of arsenite and the redox cycler juglone. While the knockdown of gamma-glutamylcysteine synthetase led to a diminished survival rate under arsenite stress conditions, GSR-1 (glutathione reductase) was shown to be essential for survival under juglone stress conditions. gsr-1 is the sole GSR encoding gene found in C. elegans. Knockdown of GSR-1 hardly affected total glutathione levels nor reduced glutathione/glutathione disulphide (GSH/GSSG) ratio under normal laboratory conditions. Nevertheless, when GSSG recycling was impaired by gsr-1(RNAi), GSH synthesis was induced, but not vice versa. Moreover, the impact of GSSG recycling was potentiated under oxidative stress conditions, explaining the enormous effect gsr-1(RNAi) knockdown had on juglone tolerance. Accordingly, overexpression of GSR-1 was capable of increasing stress tolerance. Furthermore, expression levels of SKN-1-regulated GSR-1 also affected life span of C. elegans, emphasising the crucial role the GSH redox state plays in both processes.