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Nitric oxide induced S-nitrosation causes base excision repair imbalance

Authors :
Massachusetts Institute of Technology. Department of Biological Engineering
Massachusetts Institute of Technology. Center for Environmental Health Sciences
Massachusetts Institute of Technology. Department of Chemistry
Massachusetts Institute of Technology. Department of Biology
Koch Institute for Integrative Cancer Research at MIT
Engelward, Bevin P
Engelward, Bevin P.
Parrish, Marcus Curtis
Chaim, Isaac Alexander
Nagel, Zachary D.
Tannenbaum, Steven R
Samson, Leona D
Massachusetts Institute of Technology. Department of Biological Engineering
Massachusetts Institute of Technology. Center for Environmental Health Sciences
Massachusetts Institute of Technology. Department of Chemistry
Massachusetts Institute of Technology. Department of Biology
Koch Institute for Integrative Cancer Research at MIT
Engelward, Bevin P
Engelward, Bevin P.
Parrish, Marcus Curtis
Chaim, Isaac Alexander
Nagel, Zachary D.
Tannenbaum, Steven R
Samson, Leona D
Source :
Prof. Engelward
Publication Year :
2020

Abstract

It is well established that inflammation leads to the creation of potent DNA damaging chemicals, including reactive oxygen and nitrogen species. Nitric oxide can react with glutathione to create S-nitrosoglutathione (GSNO), which can in turn lead to S-nitrosated proteins. Of particular interest is the impact of GSNO on the function of DNA repair enzymes. The base excision repair (BER) pathway can be initiated by the alkyl-adenine DNA glycosylase (AAG), a monofunctional glycosylase that removes methylated bases. After base removal, an abasic site is formed, which then gets cleaved by AP endonuclease and processed by downstream BER enzymes. Interestingly, using the Fluorescence-based Multiplexed Host Cell Reactivation Assay (FM-HCR), we show that GSNO actually enhances AAG activity, which is consistent with the literature. This raised the possibility that there might be imbalanced BER when cells are challenged with a methylating agent. To further explore this possibility, we confirmed that GSNO can cause AP endonuclease to translocate from the nucleus to the cytoplasm, which might further exacerbate imbalanced BER by increasing the levels of AP sites. Analysis of abasic sites indeed shows GSNO induces an increase in the level of AP sites. Furthermore, analysis of DNA damage using the CometChip (a higher throughput version of the comet assay) shows an increase in the levels of BER intermediates. Finally, we found that GSNO exposure is associated with an increase in methylation-induced cytotoxicity. Taken together, these studies support a model wherein GSNO increases BER initiation while processing of AP sites is decreased, leading to a toxic increase in BER intermediates. This model is also supported by additional studies performed in our laboratory showing that inflammation in vivo leads to increased large-scale sequence rearrangements. Taken together, this work provides new evidence that inflammatory chemicals can drive cytotoxicity and mutagenesis via BER imbalance.<br />National Cancer Institute (U.S.) (Grant P01-CA026731)<br />National Institute of Environmental Health Sciences (Grant P30-ES002109)

Details

Database :
OAIster
Journal :
Prof. Engelward
Notes :
application/pdf, en_US
Publication Type :
Electronic Resource
Accession number :
edsoai.on1141881676
Document Type :
Electronic Resource