MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University , Beijing 100084, China.
Beijing Chaoyang Hospital Affiliated to Capital Medical University , Chaoyang District, Beijing 100020, China.
J Proteome Res. 2018 Mar 2;17(3):1091-1100. doi: 10.1021/acs.jproteome.7b00761. Epub 2018 Jan 30.
Glutaredoxin-1 (Grx1) catalyzes deglutathionylation with glutathione as a cofactor. Accumulating evidence indicates important roles for Grx1 and S-glutathionylation in the aging process; however, further exploration of Grx1-regulated cellular processes is important to understand the functions of Grx1 in aging. In the present study, we constructed stable Grx1 knockdown or overexpression human cell lines. Grx1 silencing significantly decreased the cellular ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG) (GSH/GSSG ratio), resulting in excessive reactive oxygen species (ROS) accumulation, whereas Grx1 overexpression decreased cellular ROS levels. Grx1 silencing also increased glutathionylation of DJ-1 and HSP60, contributing to decreased mitochondrial spare respiration capacity and ATP production. We applied quantitative proteomics to identify differentially expressed proteins between Grx1 knockdown and control cells and showed that Grx1 silencing inactivated DNA replication and damage repair pathways. p53 signaling was activated by Grx1 silencing, which inhibited the CDK4-mediated G1-S transition, resulting in G1 phase cell-cycle arrest and cell senescence, a known hallmark of aging. Taken together, our results indicate that Grx1 regulates DNA replication and damage repair processes and is a potential therapeutic target for aging-related diseases.
谷氧还蛋白 1（Grx1）以谷胱甘肽作为辅助因子催化去谷胱甘肽化。越来越多的证据表明 Grx1 和 S-谷胱甘肽化在衰老过程中起着重要作用；然而，进一步探索 Grx1 调节的细胞过程对于理解 Grx1 在衰老中的功能很重要。在本研究中，我们构建了稳定的 Grx1 敲低或过表达的人细胞系。Grx1 沉默显著降低了细胞内还原型谷胱甘肽（GSH）与氧化型谷胱甘肽（GSSG）的比例（GSH/GSSG 比值），导致活性氧（ROS）过度积累，而过表达 Grx1 则降低了细胞内 ROS 水平。Grx1 沉默还增加了 DJ-1 和 HSP60 的谷胱甘肽化，导致线粒体备用呼吸能力和 ATP 产生减少。我们应用定量蛋白质组学来鉴定 Grx1 敲低和对照细胞之间差异表达的蛋白质，并表明 Grx1 沉默使 DNA 复制和损伤修复途径失活。Grx1 沉默激活了 p53 信号通路，抑制了 CDK4 介导的 G1-S 过渡，导致 G1 期细胞周期停滞和细胞衰老，这是衰老的一个已知特征。总之，我们的结果表明 Grx1 调节 DNA 复制和损伤修复过程，是与衰老相关疾病的潜在治疗靶点。
