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Epigallocatechin Gallate-Mediated Cell Death Is Triggered by Accumulation of Reactive Oxygen Species Induced via the Cpx Two-Component System in Escherichia coli
The high antimicrobial activity of epigallocatechin gallate (EGCG), the most bioactive component of tea polyphenol with a number of health benefits, is well-known. However, little is known about the mechanism involved. Here, we discovered the relationship between reactive oxygen species (ROS), the C...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Frontiers Media S.A.
2018
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5819313/ https://www.ncbi.nlm.nih.gov/pubmed/29497416 http://dx.doi.org/10.3389/fmicb.2018.00246 |
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author | Nie, Tao Zhang, Chenlu Huang, Antian Li, Ping |
author_facet | Nie, Tao Zhang, Chenlu Huang, Antian Li, Ping |
author_sort | Nie, Tao |
collection | PubMed |
description | The high antimicrobial activity of epigallocatechin gallate (EGCG), the most bioactive component of tea polyphenol with a number of health benefits, is well-known. However, little is known about the mechanism involved. Here, we discovered the relationship between reactive oxygen species (ROS), the Cpx system, and EGCG-mediated cell death. We first found an increase in ampicillin resistance as well as the transcription level of a LD-transpeptidase (LD-TPase) involved in cell wall synthesis; ycbB transcription was upregulated whereas that of another LD-TPase, ynhG, appeared to be constant after a short exposure of Escherichia coli to sub-inhibitory doses of EGCG. Additionally, the transcription level of cpxP, a downstream gene belonging to the Cpx regulon, was positively correlated with the concentration of EGCG, and significant upregulation was detected when cells were treated with high doses of EGCG. Through analysis of a cpxR deletion strain (ΔcpxR), we identified a constant ROS level and a notable increase in the survival rate of ΔcpxR, while the ROS level increased and the survival rate decreased remarkably in the wild-type strain. Furthermore, thiourea, which is an antioxidant, reduced the ROS level and antimicrobial activity of EGCG. Taken together, these results suggest that EGCG induces ROS formation by activating the Cpx system and mediates cell death. |
format | Online Article Text |
id | pubmed-5819313 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-58193132018-03-01 Epigallocatechin Gallate-Mediated Cell Death Is Triggered by Accumulation of Reactive Oxygen Species Induced via the Cpx Two-Component System in Escherichia coli Nie, Tao Zhang, Chenlu Huang, Antian Li, Ping Front Microbiol Microbiology The high antimicrobial activity of epigallocatechin gallate (EGCG), the most bioactive component of tea polyphenol with a number of health benefits, is well-known. However, little is known about the mechanism involved. Here, we discovered the relationship between reactive oxygen species (ROS), the Cpx system, and EGCG-mediated cell death. We first found an increase in ampicillin resistance as well as the transcription level of a LD-transpeptidase (LD-TPase) involved in cell wall synthesis; ycbB transcription was upregulated whereas that of another LD-TPase, ynhG, appeared to be constant after a short exposure of Escherichia coli to sub-inhibitory doses of EGCG. Additionally, the transcription level of cpxP, a downstream gene belonging to the Cpx regulon, was positively correlated with the concentration of EGCG, and significant upregulation was detected when cells were treated with high doses of EGCG. Through analysis of a cpxR deletion strain (ΔcpxR), we identified a constant ROS level and a notable increase in the survival rate of ΔcpxR, while the ROS level increased and the survival rate decreased remarkably in the wild-type strain. Furthermore, thiourea, which is an antioxidant, reduced the ROS level and antimicrobial activity of EGCG. Taken together, these results suggest that EGCG induces ROS formation by activating the Cpx system and mediates cell death. Frontiers Media S.A. 2018-02-15 /pmc/articles/PMC5819313/ /pubmed/29497416 http://dx.doi.org/10.3389/fmicb.2018.00246 Text en Copyright © 2018 Nie, Zhang, Huang and Li. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Microbiology Nie, Tao Zhang, Chenlu Huang, Antian Li, Ping Epigallocatechin Gallate-Mediated Cell Death Is Triggered by Accumulation of Reactive Oxygen Species Induced via the Cpx Two-Component System in Escherichia coli |
title | Epigallocatechin Gallate-Mediated Cell Death Is Triggered by Accumulation of Reactive Oxygen Species Induced via the Cpx Two-Component System in Escherichia coli |
title_full | Epigallocatechin Gallate-Mediated Cell Death Is Triggered by Accumulation of Reactive Oxygen Species Induced via the Cpx Two-Component System in Escherichia coli |
title_fullStr | Epigallocatechin Gallate-Mediated Cell Death Is Triggered by Accumulation of Reactive Oxygen Species Induced via the Cpx Two-Component System in Escherichia coli |
title_full_unstemmed | Epigallocatechin Gallate-Mediated Cell Death Is Triggered by Accumulation of Reactive Oxygen Species Induced via the Cpx Two-Component System in Escherichia coli |
title_short | Epigallocatechin Gallate-Mediated Cell Death Is Triggered by Accumulation of Reactive Oxygen Species Induced via the Cpx Two-Component System in Escherichia coli |
title_sort | epigallocatechin gallate-mediated cell death is triggered by accumulation of reactive oxygen species induced via the cpx two-component system in escherichia coli |
topic | Microbiology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5819313/ https://www.ncbi.nlm.nih.gov/pubmed/29497416 http://dx.doi.org/10.3389/fmicb.2018.00246 |
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