Control of Trx1 redox state modulates protection against methyl methanesulfonate-induced DNA damage via stabilization of p21.
Thioredoxin 1 (Trx1) is known to play an important role in protecting against cell death. However, the mechanism for control of Trx1 in cell death resulting from DNA damage has not been fully investigated. In this study, we used the DNA-damaging agent methyl methanesulfonate (MMS) to investigate the protective effects of Trx1 against DNA damage and cell death in HEK293 cells. We found that MMS application caused dose-dependent changes in the Trx1 redox state determined by redox western blotting. At lower concentrations, both reduced and oxidized Trx1 were observed, whereas the reduced band was fully oxidized at the higher concentration. Trx1 overexpression and small interfering RNA knockdown in cells revealed that reduced Trx1 after exposure to lower doses of MMS attenuated DNA damage, assessed by comet assay, and level of the DNA-damage marker histone γ-H2AX, possibly through scavenging intracellular ROS and an increase in p21 protein level via enhancing its stability. However, oxidized Trx1 lost its protective ability to DNA damage in response to higher concentration of MMS. Corresponding to the redox state control of Trx1, cell death induced by different dose of MMS was also found, by inhibiting phosphorylations of p38 and 4E-BP1. These results indicate that reduced Trx1 plays important protective roles against MMS-induced DNA damage and cell death, suggesting that cell protection is regulated by the intracellular redox state. Control of the redox state of Trx1 and its regulating proteins may offer a novel therapeutic strategy for the control of cancer.
Department of Neurobiology, Capital Medical University, Beijing Institute for Brain Disorders and Key Laboratory for Neurodegenerative Disorder, Ministry of Education.
Li
L
Gu
Department of Neurobiology, Capital Medical University, Beijing Institute for Brain Disorders and Key Laboratory for Neurodegenerative Disorder, Ministry of Education.
Wei
W
Gao
Department of Neurobiology, Capital Medical University, Beijing Institute for Brain Disorders and Key Laboratory for Neurodegenerative Disorder, Ministry of Education.
Hui Min
HM
Yang
School of Basic Medical Science, Capital Medical University, Beijing 100069 and.
Bei Bei
BB
Wang
School of Basic Medical Science, Capital Medical University, Beijing 100069 and.
Xiao Na
XN
Wang
Department of Internal Medicine, Shaoxing Second Hospital, Zhejiang 312000, China.
Jianguo
J
Xu
Department of Neurobiology, Capital Medical University, Beijing Institute for Brain Disorders and Key Laboratory for Neurodegenerative Disorder, Ministry of Education, hzhang@ccmu.edu.cn.
Hong
H
Zhang
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D018797:Cell Cycle Proteins; D002470:Cell Survival; D020552:Comet Assay; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism*; D004249:DNA Damage; D055785:Gene Knockdown Techniques; D057809:HEK293 Cells; D006657:Histones / Q000378:metabolism; D006801:Humans; D048848:MAP Kinase Kinase Kinase 5 / Q000378:metabolism; D008741:Methyl Methanesulfonate / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D055550:Protein Stability; D034741:RNA, Small Interfering / Q000235:genetics; D017382:Reactive Oxygen Species; D013879:Thioredoxins / Q000235:genetics / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D018906:Antineoplastic Agents, Alkylating; C493956:CDKN1A protein, human; D018797:Cell Cycle Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; C087000:EIF4EBP1 protein, human; C468783:H2AX protein, human; D006657:Histones; D010750:Phosphoproteins; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; C491203:TXN protein, human; D013879:Thioredoxins; D008741:Methyl Methanesulfonate; D048051:p38 Mitogen-Activated Protein Kinases; D048848:MAP Kinase Kinase Kinase 5; C482858:MAP3K5 protein, human
DNA damage; cell death; methyl methanesulfonate; reactive oxygen species; thioredoxin 1