Effects of acetaldehyde-induced DNA lesions on DNA metabolism

Haruka Tsuruta,Isao Kuraoka,Kosuke Tohashi,Yuina Sonohara,Narumi Aoki Shioi,Shigenori Iwai

doi:10.1186/s41021-019-0142-7

Abstract

BackgroundAcetaldehyde, produced upon exposure to alcohol, cigarette smoke, polluted air and sugar, is a highly reactive compound that is carcinogenic to humans and causes a variety of DNA lesions in living human cells. Previously, we reported that acetaldehyde reacts with adjacent deoxyguanosine residues on oligonucleotides, but not with single deoxyguanosine residues or other deoxyadenosine, deoxycytosine, or thymidine residues, and revealed that it forms reversible intrastrand crosslinks with the dGpdG sequence (GG dimer).ResultsHere, we show that restriction enzymes that recognize a GG sequence digested acetaldehyde-treated plasmid DNA with low but significant efficiencies, whereas restriction enzymes that recognize other sequences were able to digest such DNA. This suggested that acetaldehyde produced GG dimers in plasmid DNA. Additionally, acetaldehyde-treated oligonucleotides were efficient in preventing digestion by the exonuclease function of T4 DNA polymerase compared to non-treated oligonucleotides, suggesting structural distortions of DNA caused by acetaldehyde-treatment. Neither in vitro DNA synthesis reactions of phi29 DNA polymerase nor in vitro RNA synthesis reactions of T7 RNA polymerase were observed when acetaldehyde-treated plasmid DNA was used, compared to when non-treated plasmid DNA was used, suggesting that acetaldehyde-induced DNA lesions inhibited replication and transcription in DNA metabolism.ConclusionsAcetaldehyde-induced DNA lesions could affect the relative resistance to endo- and exo-nucleolytic activity and also inhibit in vitro replication and in vitro transcription. Thus, investigating the effects of acetaldehyde-induced DNA lesions may enable a better understanding of the toxicity and carcinogenicity of acetaldehyde.

Highlights

Most carcinogens damage DNA and generate mutations in the genome [1]
EcoRI-digested linear pBluescript II SK (pBSII) DNA templates were treated with acetaldehyde and digested using the indicated restriction enzymes and the samples were loaded on a 1% agarose gel
The results indicated that acetaldehyde induced DNA lesions prevented restriction enzyme mediated digestion

Summary

Introduction

Aflatoxin B1, which is considered one of the most important fungal mycotoxins in human food, is altered into a reactive form via metabolic processes in the liver. This reactive form induces aflatoxin-DNA adducts by reacting with guanine in DNA and causes guanine to thymine trans-version mutations [2, 3]. The cancer-causing chemical benzo[a]pyrene, found in coal tar Induced DNA lesions, associated with cancer, inborn diseases and aging, interfere with replication, leading to mutations and cell death [1]. We reported that acetaldehyde reacts with adjacent deoxyguanosine residues on oligonucleotides, but not with single deoxyguanosine residues or other deoxyadenosine, deoxycytosine, or thymidine residues, and revealed that it forms reversible intrastrand crosslinks with the dGpdG sequence (GG dimer)

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Discussion

Conclusion